Hundreds of baseball players make their debut over the course of a season. However, for every Ronald Acuña and Scott Kingery, there are dozens of lesser-known prospects making their debuts who aren’t as frequently discussed. To remedy that, Alex Fast, Adam Garland, Ben Palmer and I will be doing a write-up on every single player making their MLB Debut. Inspired by the Effectively Wild podcast and Andrew Perpetua, we’ll discuss each debut’s skill set, how long they will likely remain in the majors and any other pertinent information you need to know. Each player will also be stored in a spreadsheet featuring further information (bio, D.O.B, player ID’s, etc) that can be accessed at the bottom of the article.
Here are the debuts from June 6th:
Diego Castillo (SP, Tampa Bay Rays, 24 years old)
Call Up Date: June 6th
Role: Bullpen Depth
Organization Ranking: 27th
Overall Ranking: N/A
Grades: Fastball: 70 | Slider: 55 | Control: 50 | Overall: 45
Fantasy Relevance: Worth a flier
Diego Castillo is an interesting case who seems to be a perfect fit for the Rays, an interesting add in some deeper leagues and someone to keep an eye on in shallower leagues. Don’t let the fact that he’s ranked 27th in the Rays organization fool you: the dude has incredible arm strength and has been very successful in the minors so far. Let’s start with his stuff. Castillo has a four-seam fastball that can hit 101 and consistently hits the upper 90’s with a two-seam that can get him some ground balls and an above-average slider. He’s a max-effort sort of guy who can potentially be a closer one day but realistically projects to be a set-up guy. He worked one inning in his debut and recorded 2 K’s – one off a pretty mean slider to Trea Turner that you can see below – and a groundout. Before his call-up he had a 1.03 ERA, with a 0.84 WHIP and a 32/7 K/BB ratio. You would think too that because he’s a flame thrower that he may struggle with his command but he hasn’t posted a BB/9 over 3 (with a min 10 IP). It’s tricky to say how the Rays will utilize Castillo moving forward considering how original they are with bullpen management. If he starts to see more hold opportunities, he’s someone I would be interested in picking up.
Caleb Ferguson (SP, Los Angeles Dodgers, 21 years old)
Call Up Date: June 6th
Role: Injury Fill-In
Organization Ranking: 15th
Overall Ranking: N/A
Grades:Fastball: 55 | Curveball: 55 | Changeup: 50 | Control: 50 | Overall: 45
Fantasy Relevance: Deep League Flier
The Dodgers 15th best prospect – and best LHP prospect – had a debut to forget as he only went 1.2 IP giving up 4 ER and recording 3 BB and 3 K against the Pirates. Ferguson struggled in the first but didn’t give up a run so there was some hope that maybe his shaky first inning was just nerves. However, he hit a batter to start the second and it just kept getting worse from there. In the minors so far this year Caleb has had a lot of success. Over eight starts in AA and two in AAA he’s put up a 1.53 ERA with 52 K’s and 17 BB over 47 IP. He has a mid 90’s fastball that is often difficult for hitters to square up with a high-70’s curve that he struggles to command consistently as is evident by the large jump in walk rate he saw in his minor league career. I’d be hesitant to add Ferguson to my fantasy squad for a few reasons 1) I don’t think he projects to be more than a back-end starter 2) the Dodgers have a lot of guys who will hopefully return from injury soon and I don’t see him getting more than two starts before heading back down to the minors.
Nick Martini has sort of been all over the place. Originally drafted by the St. Louis Cardinals in 2011 he was unable to make his way to the majors with that organization. He selected free agency in 2017 and was signed to a minor league contract with a spring training invite by the Oakland Athletics earlier this year. In 51 games so far at AAA he’s slashed .299 / .417 / .390. As you can already tell by the slugging he’s not much of a power guy but he does have a good eye and an above average ability to make contact. His call-up as due to an injury to Matt Joyce and I don’t see him earning too many at-bats at the major league level.
Missed a player’s debut? Read detailed reports on all 2018 MLB debuts in this spreadsheet.