+

Seattle Mariners’ 2021 Preseason Top 50 Prospects

Andy Patton ranks the Top 50 prospects in the Seattle Mariners farm system for dynasty formats.

The Seattle Mariners appear on the verge of making the highly-anticipated turn from rebuilding, like really rebuilding, to pushing all in. The rebuild has been extremely impressive, however, with general manager Jerry DiPoto pulling off a handful of trades that replenished the team’s barren farm system in a major way.

Additions like Jarred Kelenic, Taylor Trammell, Andres Munoz, and Juan Then all came via trade, while the team has also done well on the international market with Julio Rodriguez and Noelvi Marteand via the draft with a trio of promising young arms in Logan Gilbert, Emerson Hancockand George Kirby.

All that, coupled with recently graduated prospects like Kyle Lewis, Justus Sheffieldand Evan Whitepoints to a team that could/should end the team’s 20 year playoff drought in a year or so. From a dynasty perspective, it’s time to buy, buy, buy, as this system is chalk full of talented future big leaguers, not just 1-5 but arguably as far as 20 deep.

Here’s a look at the top 50 prospects, and how to evaluate them in your dynasty leagues.

Note: These Top 50 lists are all done through a fantasy baseball-focused lens. Many players who are ranked higher or lower on other platforms will get a boost here. For example, players who profile as middle relievers or glove-first infielders likely won’t have much fantasy relevance, so they won’t be ranked as highly. 

 

1. OF Jarred Kelenic

 

Age: 21

Highest level: Double-A

For the Mariners, the top two are really 1A and 1B. It’s dealer’s choice when deciding between Jarred Kelenic and Julio Rodriguez, a pair of consensus top five prospects in all of baseball. I ranked Kelenic first because I value proximity to the big leagues when looking at two relatively equal prospects (more on that later) but both have an exceptional crop of tools.

Kelenic, the prize return in the disastrous Robinson Cano/Edwin Diaz trade (disastrous if you’re a Mets fan, I should say) is a true five-tool stud who is nearly ready for the big leagues – and is a near lock to be in Seattle’s outfield at some point in 2021, alongside Kyle Lewis and potentially Taylor Trammellwith Rodriguez a year (or less) behind.

Don’t overthink it – Kelenic has the tools to be a future first round pick in all fantasy baseball formats for the next 15 years, and you don’t want to miss out on him if you can avoid it.

ETA: 2021

 

2. OF Julio Rodriguez

 

Age: 19

Highest Level: High-A

Like I said, 1A and 1B. Many places rank Rodriguez ahead of Kelenic, and a lot of places have him the No. 2 prospect in all of baseball behind Wander Francobut I still like Kelenic because of his proximity to the big leagues, and slightly more speed, which is a slight tiebreaker with all else considered.

Rodriguez, at age 18, absolutely tore through Single-A and Double-A pitching in 2019 while being one of the youngest players in the league. He oozes potential, with a beautiful swing that should produce 30+ home runs annually, and the kind of plate discipline that scouts drool about – especially for a kid his age.

You likely don’t need to be told much more about Rodriguez, he’s a certifiable stud and a prospect who should be highly targeted in all dynasty formats. It’s not crazy to imagine he is the top teenager selected in dynasty formats, and, like Kelenic, you won’t want to miss out here.

ETA: 2022

 

3. RHP Logan Gilbert

 

Age: 23

Highest Level: Double-A

Debating between 1 and 2 was difficult, and the debate between 3 and 4 was arguably just as difficult. I tend to favor hitters over pitchers, with proximity to the big leagues a big factor as well – two arguments that were cancelled out when evaluating 23-year-old right-handed pitcher Logan Gilbert and 19-year-old shortstop Noelvi Marte

Lists in general are difficult exercises, because everyone is looking for different things in dynasty formats. Someone who is looking to contend right away would probably value Gilbert, a safer, near-MLB ready prospect with a high floor – while another dynasty player might want to build toward the future and gamble on the tremendous upside of Marte, knowing the floor is much lower and his time in the MLB is at least three years away.

I ultimately settled on Gilbert, in part because I lean proximity in tiebreaker scenarios, in part because I talked to industry folks who I trust and got good feedback about Gilbert, and in part because – while I think he’s more of a floor prospect than an upside one – there’s still a lot of upside here, especially after seeing this video of him touching 97 with ridiculous movement on his fastball:

https://twitter.com/flbaseballranch/status/1346529325764505600?s=21

Mariners gas camp is a real thing, and as long as you can count on their pitching prospects getting velo bumps while retaining their command, they will be hot commodities on the dynasty market.

Gilbert is a safe bet to settle in as a big league No. 3 with strikeout potential – but the ceiling is ace potential and it looks like he is pushing hard to reach that threshold. He’s an easy top-50 prospect in all of baseball for me, and one of the first arms I’d happily target in dynasty drafts.

ETA: 2021

 

4. SS Noelvi Marte

 

Age: 19

Highest Level: R

Ranking Gilbert third has a lot more to do with Gilbert than it does Marte, a 19-year-old phenom who impressed everyone at the alternate training site this year, showing up with added muscle that likely precludes even more power for the star slugger – although it could easily mean a move away from shortstop over to third base, which does hurt his long term value.

Marte only has 299 professional plate appearances under his belt, all in rookie ball, but his prospect stock catapulted in the last year thanks to his stellar line at that level: .309/.371/.511 with nine home runs and 17 stolen bases.

Marte has been tagged with 80-grade speed by some scouts, and now that the power is expected to come with his added muscle, there is real 20/30 threat here if everything comes together. His value is still tied to how that hit tool matures against superior pitching in High-A and Double-A, and how his plate discipline looks, but he’s a potential top-tier fantasy stud and another guy that is firmly in my top-75 prospects

Concerns about his hit tool are still around, and he’ll need to prove he can maintain good plate discipline against superior competition, but for now he’s a toolsy middle infield prospect to keep on the radar.

ETA: 2023

 

5. RHP Emerson Hancock

 

Age: 21

Highest Level: N/A

The No. 6 pick in the 2020 MLB draft, Emerson Hancock represents the third straight right-handed pitcher the Mariners have taken in the first round – and he has the arsenal to be the best of the bunch.

Armed with a fastball that touches 99 with riding life and a trio of secondaries that have all flashed plus at times, there’s a lot of similarities between Hancock and Tigers right-hander Casey Mizewho went first overall in 2019.

Hancock possesses strong command of all his offspeed offerings, which includes a plus plus slider and a hard curveball which he relied upon more in high school than in college, but that still flashes plus. He also has a show-me changeup, and if that pitch does develop as expected he has an easy frontline starter projection.

While he has yet to throw a professional game, Hancock could be a very quick riser to the big leagues. I wouldn’t be surprised at all to see him in the big leagues for a large chunk of the 2022 season, and there’s even a chance he makes his debut at some point in 2021 – likely September.

ETA: 2022

 

6. OF Taylor Trammell

 

Age: 24

Highest Level: Double-A

The biggest prospect acquisition at last season’s trade deadline was outfielder Taylor Trammellwho joined the Mariners along with a handful of other youngsters in a deal for Austin Nola.

Trammell is on his third big league team already, with just four MiLB seasons under his belt, which I know is worrisome to a lot of fans and dynasty players. However, Trammell reportedly underwent a pretty significant swing change after moving from Cincinnati to San Diego, detailed in this great piece by Trevor Hooth, and while we don’t have a lot of video evidence to go off of (thanks COVID) we do know his load is more pronounced and his hands start further away from his body, making a smoother, quicker swing that also adds even more oomph.

He still has some swing-and-miss to his game, and his arm limits him to just left field, but I think there is potential as a solid fantasy asset here, with speed and some power to boot. He suffers a bit from prospect fatigue, but he’s just 23 years old and should be making his big league debut at some point this season. He’s a solid outfield target in most dynasty formats – and someone to keep an eye on in redraft leagues as well.

ETA: 2021

 

7. RHP George Kirby

 

Age: 22

Highest Level: Low-A

The third of Seattle’s first round arms in the past three years, George Kirby is not a prospect you want to dismiss, even if he is the third best arm in Seattle’s farm system.

In nine starts at short-season in 2019, Kirby posted a 25/0(!) K/BB ratio, and while that’s entirely too small of a sample size, it’s not hard to see the appeal. More than that, Kirby is reportedly another beneficiary of Seattle’s gas gamp, hitting 99 with regularity during bullpens while bulking up quite a bit over the last year or so.

Kirby’s command is absolutely incredible, and he has four pitches that have all flashed plus. He’s about a year behind Gilbert development wise, but the leaps he has made seem all but certain to happen with Kirby as well – and he could be an easy top-50 prospect by the time this year is up – maybe even top-30.

ETA: 2022

 

8. OF Zach DeLoach

Age: 22

Highest Level: N/A

DeLoach is a tough player to evaluate. I took him in our recent first-year player mock draft, and I’m a believer in his very recent breakout. However, it’s hard to ignore the fact that he was pretty bad at Texas A&M for two straight seasons before breaking through in a major way in the summer of 2019, winning the batting title in the Cape Cod league by hitting .353 and parlaying that into a massively successful 2020 season with the Aggies.

Of course, one good summer and a handful of good games against inferior opponents in 2020 shouldn’t completely wipe out two bad years in college – which is what makes him a tricky prospect to evaluate.

DeLoach has plus plate discipline, which often resulted in him being too passive early in his collegiate career. The M’s are obviously banking on the switch that occurred in 2019, when he started impacting the ball a lot harder and earlier in counts, will translate into the minor leagues.

This ranking is dependent on how risk-averse you are as a dynasty player, but I’m more than willing to bet on DeLoach in deeper dynasty leagues, and he’s a player I will be watching very closely as he makes his pro debut in 2021.

ETA: 2023

 

9. C Cal Raleigh

 

Age: 24

Highest Level: Double-A

Considering what happened the last time the Mariners had a power-hitting catcher with strikeout issues (Mike Zunino), I can see why there are people concerned about Cal Raleigh, both as a real-life prospect and from a dynasty perspective.

However, Zunino was rushed to the majors far too quickly, a mistake the team has clearly learned from. Raleigh had barely begun his first stint at Double-A when he surpassed the number of plate appearances Zunino had in the minors before he made his big league debut. The Mariners also chose not give Raleigh a call-up in 2020, even after dealing Austin Nolachoosing instead to (likely) promote him alongside Logan Gilbert at some point in 2021.

Raleigh blasted 29 home runs with 82 RBI in 2019, and his good defensive instincts make him a near-lock to stay behind the plate. He has 30+ home run potential if he gets a regular starting gig, but those strikeout issues will seriously limit his contributions elsewhere.

Catcher is a risky spot in dynasty formats, but Raleigh is one of the few I’m high on—even if he comes with his baggage. For more on Seattle’s catcher of the future, I’ll refer you to an article I wrote on him last year.

ETA: 2021

 

10. RHP Juan Then

 

Age: 19

Highest Level: Single-A

Another beneficiary of the team’s gas camp, Seattle initially shipped Juan Then to the Yankees after the 2017 season, but they reacquired him in the Edwin Encarnacion trade ahead of the 2019 campaign.

Then sits in the mid-90’s with his fastball, although recent video shows him getting up into the high-90’s – hence why he moved from No. 17 to No. 10 on this list, even without a minor league season. He also has a nasty breaking ball that should miss plenty of bats at the next level, and a developing changeup that could be plus in time as well.

Here’s a nice look at most of his arsenal, once again courtesy of Trevor Hooth.

Then is a gamble, most 19-year-old pitchers are, but he has the arsenal to turn into a high quality starter or high-end reliever – and he’s in the right system to make it all come together.

ETA: 2024

 

11. RHP Andres Muñoz

 

Age: 21

Highest Level: MLB

The second prospect acquired in the big Austin Nola trade, there are many within the industry who believe Muñoz, not Taylor Trammellwill be the best piece to move north in that deal.

Despite being just 21 years old, Muñoz already has big league experience under his belt – having thrown 23 innings for the Padres in 2019, even earning a save in the process.

While the team will have to wait until mid season at the earliest to see him in action, thanks to Tommy John surgery, Muñoz will absolutely be worth the wait. The six-foot-two flame-thrower has a legitimate 80-grade fastball that easily gets into the triple digits with riding life. He pairs that with a wicked slider, a true two-pitch pitcher with electric stuff and spotty command – all too familiar to Mariners fans who remember the early part of Edwin Diaz’s career.

Muñoz will be more of the same, and while ranking strictly relief pitcher prospects this high is normally a no-go for me, I believe Muñoz has the potential to be a top-five closing option as soon as the end of this season, and there is a ton of value in a top-tier closer with his strikeout potential – especially one who is still so young.

ETA: 2021 (TJ – expected healthy in June)

 

12. LHP Brandon Williamson

 

Age: 22

Highest Level: Low-A

The Mariners drafted Brandon Williamson as a very high-risk, high-reward left-hander in the second round of the 2019 draft. He only tossed 15.1 innings at Low-A to finish the 2019 season, and obviously did not throw professionally at all in 2020 – so unfortunately there is not a ton to go off here.

He did show a mid-90s fastball with elite strikeout rates, thanks to his riding life and plus extension – another trait of Mariners pitchers prospects – as well as a very nice curveball and a slider that’s more like a cutter, but a pitch the Mariners really like as an organization.

It’s hard to know what exactly the Mariners have in Williamson just yet, but he did post a nice 25/5 K/BB ratio in 2019. If his command stays strong and his velocity ticks up, which gas camp should help with, he’ll be yet another pitching prospect worth paying close attention to in this system.

ETA: 2022

 

13. RHP Isaiah Campbell

 

Age: 22

Highest Level: N/A

A lot of what was written about Williamson applies to Campbell as well, save for two key things: Campbell is right-handed, and he did not pitch at all in 2019 after the team selected him in the second round.

Campbell has a plus fastball and a nice slider that, like Williamson’s, looks like a hard cutter at times. He’s also made the decision to scrap his changeup for a splitter that scouts think could give him a solid third offering.

Much like Williamson, he’s a tough player to rank without having seen much (in this case any) of him professionally. 2021 will be a big year for both these intriguing, high-upside arms.

ETA: 2022

 

14. OF Jonatan Clase

 

Age: 17

Highest Level: R

Outfielder Jonatan Clase has been on the rise ever since a postseason report indicated he had gained a ton of weight, potentially adding some power to his frame. That’s huge news after he slashed a very nice .300/.434/.444 with 31 stolen bases and a 17.8% walk rate in rookie-ball in 2019.

Obviously there’s no guarantee he’ll start smashing home runs, but if he does, he could be a big-time riser. Best to get in early in deeper dynasty leagues, as he may not be available for long.

ETA: 2023

 

15. 3B Austin Shenton

 

Age: 22

Highest Level: Single-A

Austin Shenton was the Mariners’ fifth-round pick in 2019, and he blasted seven home runs with a .298 average in 198 at-bats split between short-season and Single-A in his first taste of pro ball.

An undersized third base prospect with a hit tool that projects higher than his power, Shenton is similar to No. 20 ranked prospect Joe Rizzo, although his glove work is more questionable and he has yet to prove himself beyond a few hundred at-bats. Still, if he proves he can tap into that power, he’ll shoot up this list.

ETA: 2022

 

16. 3B Tyler Keenan

Age: 21

Highest Level: N/A

Seattle’s fourth round pick in 2020 was hulking slugger Tyler Keenana six-foot-four behemoth out of Ole Miss who hit seven home runs with 33 RBI in college during the shortened season, with those 33 RBI being second in Division-1 during that season.

It’s rare to see a recent fourth round pick this high – especially in a pretty loaded system – but we are talking about a guy with light tower power who also commanded the zone really well in college, and that combination of skills often paints the picture of someone with serious fantasy potential down the line.

Keenan almost certainly won’t stick at 3B long term, and his bat will have to be very good for him to be relevant as a 1B/DH type, but for now he’s a very interesting hitting prospect in this system, and one I am keeping a close eye on.

ETA: 2023

 

17. RHP Sam Carlson

 

Age: 22

Highest Level: R

I’m lower on Sam Carlson than most simply because injuries have absolutely ravaged his career already, and thanks to them and the lack of a minor league season in 2020, he is now a 22-year-old high school draft pick who has thrown just three professional innings.

There is still a lot to like about his profile: A 6’4″ frame, a fastball that touches 97 mph, and a slider and changeup that scouts both believe could be plus offerings. However, until I see him healthy over a full season, I am hesitant to invest too much in dynasty leagues.

Of course, Kyle Lewis was a highly touted draft pick who was written off by analysts after suffering a gruesome injury, so there is still some cause for hope, especially after Carlson was able to throw off the bump in the fall.

2021, more so than most of Seattle’s minor leaguers, will be a big year for Carlson.

ETA: 2023

 

18. RHP Sam Delaplane

 

Age: 25

Highest Level: Double-A

How you feel about my Sam Delaplane ranking is entirely dependent on how you feel about gambling on  strictly relief pitchers in dynasty formats. Delaplane is among the best pure relief prospects out there, having posted an obscene 120/23 K/BB ratio with a 2.23 ERA (1.99 FIP) and a 0.84 WHIP split between High-A/Double-A in 2019.

There is certainly enough here to imagine Delaplane as a future closer in Seattle, possibly as soon as 2021 (although the arrival of Andres Muñoz may challenge that) but his fantasy value is virtually nonexistent unless he falls right into that role—which makes me hesitant.

If you like gambling on RP-only prospects, Delaplane is your guy. If you’d rather pursue potential starters or hitters, I wouldn’t blame you.

ETA: 2021

 

19. OF Jake Fraley

 

Age: 25

Highest Level: MLB

Heading into 2020, it seemed like a near certainty that Jake Fraley would be on the Opening Day roster, with many believing he would be the team’s starting right fielder.

Instead, Fraley stayed at the team’s alternate site for nearly a month while guys like Jose Marmolejos, Tim Lopes and Sam Haggerty took reps in the outfield. He eventually game up and appeared in just seven games, hitting .154 with a 37.9% strikeout rate before going on the injured reserve.

Fraley now has a .152/.200/.227 slash line in 70 big league plate appearances, along with a 2.9% walk rate and a 35.7% strikeout rate. That sample is tiny, and he had a lot of pedigree prior 2019, but the complete lack of trust by Seattle’s brass to give him playing time – mixed with his poor performance when he has been up, has me very, very down on him going forward. I don’t think his big league future will happen in Seattle with Kelenic, J-Rod, Lewis and Trammell all around, and I wouldn’t be surprised if he is traded before Opening Day.

ETA: 2021

 

20. 3B Joe Rizzo

Age: 21

Highest Level: High-A

Joe Rizzo has always had a strong hit tool, but a lack of size and limited power has hurt his stock. He hit a career-high 10 home runs with 30 doubles and three triples at High-A in 2019, while also slashing .295/.354/.423.

Defensively he is a lock to stick at third base, and while he may never be a big time slugger, his advanced feel at the plate could make him a solid big league regular. The team’s addition of Ty France and the presence of fellow prospects Austin Shenton and Tyler Keenannot to mention the next guy on the list, Kaden Polcovichmake me less confident Rizzo is the next guy up at third base for Seattle – and a utility role could end up being the plan – obviously hurting his fantasy value.

ETA: Late 2021

 

21. 2B Kaden Polcovich

 

Age: 21

Highest Level: N/A

Seattle’s third round pick in 2020, switch-hitter Kaden Polcovich is a do-it-all player who profiles nicely as an above-average utility player, a la Mark McLemore (throwback for those M’s fans who have suffered since 2001).

Polcovich is a better hitter from the right side, but he makes enough contact from both sides to be a big league hitter. He is a smart runner on the bases and has a little pop, but looks more like a gap power guy than a home run hitter, and probably doesn’t possess the speed to be a huge stolen base guy.

Still, the work ethic is off the charts, and the ability to play multiple positions and hit from both sides of the dish could make him a useful MLB player and, at his peak, a useful fantasy asset.

ETA: 2023

 

22. RHP Ljay Newsome

 

Age: 24

Highest Level: MLB

I was hesitant about Newsome heading into last season, despite his ridiculous performance in 2019 across three levels (169/17 K/BB ratio) and what we saw from him in the big leagues last year somewhat confirmed a lot of those concerns.

Newsome has incredible command, as evidenced by his 1.5% walk rate, but he also posted just a 13.2% strikeout rate and a 5.17 ERA, 1.34 WHIP and even uglier 5.74 FIP in 15.2 big league innings.

That’s kind of what I think Newsome is; a command-heavy No. 5 starter who doesn’t have good enough stuff to miss bats at the big league level, which will result in him getting hit around a lot. I think he could be an okay streaming option at times, and maybe he’ll make some adjustments to his pitch mix, but I get serious swingman vibes here, and not sure I’m willing to invest much in fantasy.

ETA: 2021

 

23. RHP Connor Phillips

 

Age: 19

Highest Level: N/A

Phillips was Seattle’s competitive balance pick in 2020, and while he was their third player selected in the draft I have him ranked fifth from the class, mostly because of concerns about his high-effort delivery and slight frame – which make me think he may have a future in a big league bullpen.

Phillips already gets into the mid-90’s with his fastball, and Seattle’s gas camp could easily get him into the high-90’s, but until I see how that stuff looks as a starter in pro games, I’m going to be cautious here.

ETA: 2023

 

24. LHP Brayan Perez

 

Age: 20

Highest Level: Low-A

Just 20 years old, Brayan Perez pitched well in a small cameo at short-season last year. The international signee has an advanced feel for pitching and plus command, but until his frame builds out, it is hard to project his velocity and pitch mix. He’s in the low 90s now, at least with the most recent data that we have, but if he adds muscle and maintains his command while getting into the mid-90s, he could be a stud.

It’s a waiting game with Perez, but he’s certainly not among the worst gambles you could make.

ETA: 2023

 

25. 1B/OF Jose Marmolejos

 

Age: 28

Highest Level: MLB

The Mariners signed longtime Nationals farmhand Jose Marmolejos to a minor league deal with an invitation to spring training in 2019, coming off a season where he hit .315/.366/.545 with 16 home runs at Triple-A.

The signing paid off, as Marmolejos ended up playing a big role in the Emerald City, appearing in 35 games and slashing .206/.261/.411 with six home runs and 18 RBI.

Marmolejos has always had solid power, but he is almost certainly locked in as a left-handed platoon bat – which has limited value outside of very deep dynasty leagues and possibly daily fantasy formats.

ETA: 2021

 

26. 2B/SS Jose Caballero

 

Age: 24

Highest Level: High-A

Jose Caballero came over the Mariners in the Mike Leake trade back in July of 2019, and while his .256 average was, well, average, he did boast a nice 11.0% walk rate and a 13.8% strikeout rate in High-A.

Caballero’s calling card is his speed, having swiped 33 total bases in 2019 between three levels. He’ll need to prove he can hit enough to get on base at the big league level, but as a middle infielder with speed to burn he’s not the worst dynasty dart throw for those with the need for speed.

ETA: Late 2022

 

27. 2B/SS Donovan Walton

 

Age: 26

Highest Level: MLB

Donovan Walton has now made small cameos in the big leagues in each of the past two seasons, going 5-for-29 with a double, three RBI, 10 strikeout and four walks.

He did have a very strong campaign at Double-A in 2019, where he hit .300/.390/.427 with 11 home runs and 10 steals, and while the early results haven’t been great – all signs point to him developing into a utility infielder capable of playing all across the diamond, with a little pop and some speed.

Walton has plus plate discipline and enough power/speed to have an impact in deeper fantasy leagues as a utility player, and could be worth a look if he ever steps into a starting role. It’s nothing special, but these players often have some fantasy relevance and are worth looking into in deep leagues.

ETA: 2021

 

28. RHP Adam Hill

 

Age: 23

Highest Level: Single-A

Adam Hill is a big right-hander with a solid fastball-changeup combo that the Mariners acquired for Omar Narvaez last offseason. He has command issues that he’ll need to work through, along with durability concerns, but he has the tools to be a solid mid-rotation arm if he can get through all of that.

ETA: 2022

 

29. RHP Wyatt Mills

 

Age: 25

Highest Level: Double-A

Wyatt Mills is a sidearming right-handed reliever with spin rate numbers through the roof, drawing tons of comparisons to longtime big league closer Steve CishekWhile that is probably the best-case scenario, at least from a fantasy perspective, he is likely going to settle in as a middle relief option against tough righties, limiting his fantasy value.

While he gets the nod over the plethora of other middle relief prospects the Mariners have because of his strong strikeout numbers, he is still not likely a target in most formats unless he is pitching in the ninth, or your league values holds and/or K/9.

ETA: 2021

 

30. RHP Damon Casetta-Stubbs

Age: 21

Highest Level: High-A

My initial ranking of Damon Casetta-Stubbs was lower than this, but I was talked into moving him up by Trevor Hooth, who highlighted his wicked curveball in the below clip:

Casetta-Stubbs also has a nice fastball and a potentially plus slider, and while he has a ways to go – he is in the right system to maximize his velocity and command. He’s a riser in a system full of them, and one worth paying close attention to in deeper dynasty formats.

ETA: 2024

 

31. C Carter Bins

 

Age: 22

Highest Level: Low-A

An 11th-rounder in 2019, Carter Bins hit seven home runs and swiped five bases at Everett in his first professional season.

He has a strong walk rate but a 28% strikeout rate, and unless he makes more contact, his power/speed combo won’t be worth much. However, catchers are really hard to come by and ones who show even a modicum of potential should be kept under close watch, hence the sharp move upward from last year’s ranking.

ETA: 2023

 

32. RHP Joey Gerber

 

Age: 23

Highest Level: MLB

Joey Gerber is another strict relief-only pitching prospect, but his 97 mph fastball with plus spin rate could make him among the best out of the bunch, and his slider is graded plus as well, making him a potential late-inning weapon. Of course, things did not go quite as planned in 15.2 big league innings last year, as he posted a passable 4.02 ERA but with an ugly 9.7% strikeout rate and an 8.1% walk rate.

It’s hard to put too much stock into that small of a sample, but Gerber’s command has always been suspect and his delivery is pretty wonky, so he’ll need to prove he can hone his stuff in and start missing bats before he will be a real player in the late inning mix.

ETA: 2021

 

33. OF Luis Liberato

 

Age: 25

Highest Level: Triple-A

Luis Liberato has flashed some power and some speed during his long career in Seattle’s farm system, and his time in High-A last year was pretty solid – with seven home runs, four steals and a .283/.360/.440 slash line.

He has the tools to be a quality fourth outfielder, but it has taken him a long time to put it all together, and at age 25 and with a very crowded mix of outfielders around him, there is some doubt he ever will. If he doesn’t debut in 2021, it’s probably curtains for him – at least in a Seattle uniform.

ETA: 2021

 

34. OF Dom Thompson-Williams

 

Age: 25

Highest Level: Double-A

Dom Thompson-Williams followed up his stellar 2018 season in the Yankees system with a bit of a dud in his first year with Seattle after coming over in the James Paxton trade. DTW still hit 12 home runs and swiped 15 bases, all at Double-A, but he hit just .234/.298/.391 with an ugly 31.7% strikeout rate.

His power/speed combo is what makes him an interesting dynasty target, but at this point he is almost certainly a career fourth outfielder, and unless those strikeout numbers improve a lot he may not even be that.

ETA: 2021

 

35. OF Braden Bishop

 

Age: 27

Highest Level: MLB

As you can see, I am lower on Braden Bishop than most. The UW product is a fan-favorite (and for good reason) but the power/speed combination that scouts love just has not showed up in the past few years. He has stolen just eight bases since 2017, with only 16 home runs.

Injuries have played a factor, but Bishop looks far more like a defense-first fourth outfielder with limited offensive potential, which doesn’t excite me in fantasy formats.

The last two seasons have seen Bishop take 94 trips to the plate, with a strikeout rate over 30%, a walk rate below 6%, a batting average below .150 and zero home runs with one steal. Considering Seattle’s outfield depth, and who is on the way up, I don’t see much chance for fantasy relevance here.

ETA: 2021

 

36. RHP Logan Rinehart

Age: 23

Highest Level: Single-A

Rinehart was a starter at Cal Baptist who threw well in relief in the cape, enough for the Mariners to take him in the 16th round in 2019 and convert him full-time into a reliever. He pitched well enough to earn a call up to Single-A, where he posted a 3.52 ERA, 2.62 FIP, and a nice 19/3 K/BB ratio.

He filled out and looked really good in spring training last year, and reports about his performance at the alternate site were very encouraging, but he’s a middle relief profile for now until we see more of him against live hitters.

ETA: 2023

 

37. RHP Ty Adcock

 

Age: 23

Highest Level: N/A

Adcock and Rinehart are lumped together with similar profiles, as reliever-type prospects taken in the 2019 draft with little, or in the case of Adcock, no MiLB experience. A former catcher, Adcock gets up to 98 with the heater and 92 with the hard slider/cutter, a pitch that could be plus as he learns how to refine it.

Again, like Rinehart, it’s hard to know exactly what the Mariners have here – but he’s worth keeping an eye on.

ETA: 2023

38. SS Juan Querecuto

 

Age: 20

Highest Level: R

2019 was a forgettable year statistically for shortstop Juan Querecuto, whom the Mariners paid big money to sign as an international free agent in the 2017-18 signing period. In just 93 plate appearances, Querecuto only hit .203 with a nearly 38% strikeout rate and no home runs.

Known as a glove-first prospect, Querecuto needs to add muscle to his 6’2″ frame if he ever wants to hit at the big league level. If he does, his glove should allow him to start—making him a high-risk, high-reward dynasty target.

ETA: 2023

 

39. RHP Taylor Dollard

 

Age: 21

Highest Level: N/A

Dollard was Seattle’s fifth and final selection in the 2020 MLB draft, a right-hander out of Cal Poly who dominated during the abbreviated 2020 season after a strong showing in the cape – which if you read the profile on Zach DeLoach you’ll see some similarities.

Additionally, Dollard has strong command of his four-pitch mix, and if he can maintain with an expected velocity bump (hello gas camp) the team could have themselves a solid fifth starter or swingman type here.

ETA: 2023

 

40. RHP Will Vest

 

Age: 25

Highest Level: Triple-A

Seattle turned some heads with their selection of Tigers right-hander Will Vest in the Rule 5 Draft. Vest is an unknown 25-year-old reliever who posted a 5.33 ERA in Double-A in 2019 – and while that may not be too exciting there is some reason for optimism – courtesy of our very own Trevor Hooth:

I’m not quite ready to go as far as Trevor (who should get co-writing credit for this article) but I do think the Mariners got themselves a reliever who is ready to take a big leap performance-wise in 2021, although he’ll have to iron out the kinks against big league pitching or else be sent back to Detroit.

ETA: 2021

 

41. 3B Milkar Perez

 

Age: 19

Highest Level: R

Perez is a slight third base prospect with very solid feel for the strike zone (13.2% walk rate) and enough potential growth in his frame to make him a power projection.

If you squint you can see the profile of an everyday third baseman here, although a high-contact utility guy isn’t a bad compromise either.

ETA: 2025

 

42. RHP Tim Elliott

 

Age: 22

Highest Level: Low-A

The Mariners made Tim Elliott, a right-hander out of Georgia, their fourth-round pick in 2019. He responded with an excellent campaign in short-season, posting a 3.86 ERA (3.16 FIP) with a 10.38 K/9. College arms are expected to dominate the lower levels of the minors, so we will see how the stuff plays up when he reaches the full-season leagues.

ETA: 2022

 

43. RHP Gerson Bautista

 

Age: 25

Highest Level: MLB

Gerson Bautista was the third piece in the Cano/Diaz trade, but his numbers in 2018-2019 were bad enough that the team let him go, before re-signing him to a minor league deal. While he’s past the point of being a prospect of note, the 25-year-old with a 70-grade fastball that routinely touches 100 remains hard to ignore, and if he can learn to command it, he’s got instant late-inning potential.

ETA: 2021

 

44. RHP Elvis Alvarado

 

Age: 21

Highest Level: R

Elvis Alvarado is a converted outfielder who hit 100 on the gun in 2019 with wicked movement. His slider is periodically good, and his command is almost never good, but that’s what you get with a reclamation project who was hitting full-time as recently as 2018. Keep an eye out if this kid hones in his command.

ETA: 2024

 

45. OF Keegan McGovern

 

Age: 25

Highest Level: High-A

Keegan McGovern was a ninth-rounder in 2018, and he blasted 27 home runs in his first 144 professional games. He has also posted good walk rates, and poor strikeout rates, and will need to make more contact to reach his potential as power-hitting fourth outfielder.

ETA: 2022

 

46. 2B/SS Cesar Izturis Jr.

 

Age: 21

Highest Level: Triple-A

Cesar Izturis is a glove-first prospect, but he did swipe 14 bases between Low-A and Single-A in 2019, while slashing a tidy .285/.362/.341 in Everett. I have my doubts that the bat will ever be enough for him to be more than a utility/Quad-A guy, but if it does, his speed will make him fantasy relevant.

ETA: 2023

 

47. OF Cade Marlowe

 

Age: 22

Highest Level: Low-A

Cade Marlowe was a 20th-round pick by the Mariners in 2019, but he had an excellent debut campaign in short-season, hitting .301/.372/.438 with three home runs and 10 steals in 62 games played.

Hard to read too much into such a small sample size, especially for a late-round pick who was an advanced age for the level he played at, but he is worth at least monitoring in deeper formats.

ETA: 2022

 

48. RHP Devin Sweet

Age: 24

Highest Level: High-A

Devin Sweet was an undrafted senior sign in 2018 who has looked great in his pro career, transitioning from the bullpen into the starting rotation at Single-A and dominating across 12 starts in 2019.

The velocity isn’t great, but he misses bats at the top of the zone and if that ticks up (another gas camp reference) he could be a swingman type or a full-time reliever where the stuff might play up even more.

ETA: 2022

 

49. LHP Anthony Misiewicz

 

Age: 26

Highest Level: MLB

Anthony Misiewicz is an aging left-handed pitching prospect who made his way into Seattle’s bullpen picture last season, posting a 4.05 ERA with a 3.04 FIP, 30.1% strikeout rate, 7.2% walk rate and eight holds in 20 innings pitched.

It was a very nice season from the longtime Mariners prospect, but he’s unlikely to be more than a swingman or a middle reliever going forward – which holds little to know fantasy value.

ETA: 2021

 

50. OF Eric Filia

 

Age: 28

Highest Level: AAA

Eric Filia is a 28-year-old “prospect” who has been suspended for drug use multiple times and therefore has very little minor league experience, despite his age. However, he is elite—I mean elite—at making contact, never posting a strikeout rate above 10%.

A 27-year-old with virtually no power and only 35 games at Triple-A isn’t ideal, especially after he was left off the team’s 60-man roster last year, but Filia could be a speedy fourth outfielder with good contact numbers as soon as 2021—and maybe a juiced ball will let him tap into some power.

ETA: 2021

 

Others given consideration: RHP Robert Dugger, OF Julio de la Cruz, RHP Matt Festa, LHP Aaron Fletcher, RHP Yohan Ramirez, 3B Bobby Honeyman, 2B Connor Kopach

Photo: Flickr Creative Commons | Design by J.R. Caines (@JRCainesDesign on Twitter and @caines_design on Instagram)

Andy Patton

Andy is the Dynasty Content Manager here at PitcherList. He manages all of the prospect content on the site, while also contributing a weekly article on dynasty deep sleepers, and the weekly hitter and pitcher stash lists. Andy also co-hosts the Never Sunny in Seattle podcast on the PitcherList Podcast Network, and separately hosts the Score Zags Score Podcast.

3 responses to “Seattle Mariners’ 2021 Preseason Top 50 Prospects”

  1. Harry Lime says:

    Good one. Think I’ll pluck a few of these gems in my dynasty league…

    thx

  2. Shawnuel says:

    Any idea where Jose Corniell might have placed had he not been traded to Texas?
    Also, Rodriguez did not make it to AA in 2019. Low A West Virginia and and High A Modesto.

  3. Jay Morgan says:

    I think levi stoudt is like to jump into this list. But liked it much

Leave a Reply

Your email address will not be published. Required fields are marked *

Account / Login