Justus Sheffield is a guy I can’t help but like. He checks a lot of boxes. He is a former first-round pick, throws hard, misses bats, gets groundballs, is young, athletic, and works hard at his craft. He has 2 above-average pitches and throws enough strikes to be, at worst, a high-leverage reliever.
The slider has a chance to be a plus offering and flashed as such last year. The final line surrounding Sheffield’s slider didn’t look great in 2019. Opponents hit .302 against it and slugged .491 against the slider, but some bad luck may have been to blame.
The expected batting average against the pitch (based on exit velocity and launch angle) was .217 and his expected slugging percentage was just .364. Either way, we as fans can feel pretty safe about two of his offerings.
There are two questions left for Sheffield to answer. First, can he control the strike zone better than he did in 2019? Sheffield throws enough strikes, but there is a difference between throwing strikes and commanding the strike zone.
Second, what does the changeup look like? Last spring, we saw a legitimate, 55-grade changeup from Sheffield. Unfortunately, we didn’t see it much last year. He didn’t throw it much, to begin with, and when we did see it, it left a lot to be desired.
The pitch is a difference-maker for Sheffield and can take him from a #4 starter or high-leverage reliever and a #3 starter with upside. Sheffield is a near-lock to begin 2020 in Seattle’s rotation and growth in the changeup could be huge for both Sheffield and the Mariners.