A plus changeup that will allow his fastball to play exceptionally well if he can keep it low in the zone.
His fastball is in the 97th percentile of fastball spin. If given the opportunity in the Angels pen, he could ride this pitch to the back end of games.
His slider is not good and does not move much. He should throw this pitch less.
The four-seamer was not a great putaway pitch for the 25-year-old last season, with a poor BB/K ratio of 1.33 against 47 batters faced. While opposing hitters only hit .158 against the fastball, Mejia was fortunate to only surrender one longball against a 56% fly-ball rate.
Mejia’s slider was a surprising Money Pitch in 2017, posting O-swing and zone rates north of 40%, with a whiff rate of almost 19%. While the pitch didn’t replicate that success in 2018—his swinging-strike and O-swing rates both dropped—the slider still held opposing batters to just a .125 average.
With a solid 10 mph velocity difference from his four-seamer, Mejia’s changeup was fairly effective at getting batters to miss with a swinging-strike rate of 16.1%. A high BABIP resulted in a .308 batting average against last season, but otherwise the pitch was a decent putaway offering in limited use.
Mejia’s two-seamer surrendered a troubling .417 batting average against in limited use last year. With a low swinging-strike rate of 6.1%, a chase rate of just 12.5%, and middle-of-the-road velocity (91.4), the pitch clearly didn’t offer much of a challenge for opposing batters.