Next Guys Up: Yennsy Diaz

Yennsy Diaz is a 23 year old righty who is the 29th rated prospect on the team. He was signed out of the Dominican, debuted in 2019, and could be a common piece of the 2020 roster if the league chooses to expand to a 30 man roster, as reports suggest.

Diaz's 2019 wasn’t very memorable for him. He only got into one game, totaling 0.2 innings and allowing two earned runs on a hit and four walks. Prior to his debut, he spent the entire season in AA New Hampshire, the highest level he has reached. Without having ever pitched in AAA, his call up in September was unexpected for many, even after only getting into one game.

In AA, Diaz started 24 of the 26 games he appeared in, logging a sturdy 144.1 innings with a 3.74 ERA. He gave up many base runners with a 1.233 WHIP, but managed to limit the damage as he rarely gave up home runs, surrendering 12 the whole year at a rate of 0.7 HR/9. Considering his career low K/9 and an average against at .234, he likely transitioned into more of a pitch to contact player, allowing players to hit the ball, but avoiding solid contact. He limited his mistake pitches down the middle, and tried to hit the corners of the zone. Unfortunately his control is still an issue, as proven in his debut where he allowed 4 walks in 0.2 innings. The mindset for him is the same as some of the best pitchers in the league, but he simply doesn’t have the stuff yet to be successful at the major league level on an everyday basis.

Diaz's above average fastball and curveball show promise, but beyond that there isn’t much. His issue with control is a serious problem that could cost him his opportunity as a big league starter. He has long been projected as a bullpen arm, but after working on durability and muscle, he has kept a starting role for now. Should he make an MLB appearance in 2020, it will likely be out of the bullpen as he is far down on the rotation’s depth chart. He would normally start the year in AAA, but with a minor league season still in question, he could start the year with the team for developmental reasons, and could be used as a long reliever.