SF Giants Prospects: 2021 Preseason Top 31 Rankings

SF Giants top prospects: No. 27 — RHP Trevor McDonald

Age: 20
Highest Level: Rookie (AZL)
Acquired: Draft (2019)
Future-Value Grade: 40

The SF Giants finagled their draft pool in 2019 to sign Trevor McDonald away from a commitment to South Alabama with an $800,000 signing bonus. A draft-year riser after a jump in velocity, McDonald had flashed a potential plus breaking ball alongside advanced pitchability. An unorthodox delivery does accentuate his stuff but also leads some to project a move to the bullpen.

Aside from his mechanics, McDonald lacks the premium repertoire to stick in the rotation without another solid big-league offering. He occasionally showed a changeup in high school but never found much consistency with the pitch. If he sticks as a stater, it will probably need to be at least a 45-grade pitch.

Granted, his scrawny 6’2” frame could be a source of some more upside as well. Even after adding 15 pounds heading into his final prep season, McDonald still has room to fill out. His fastball already jumped from 86-88 mph to 91-94 mph, and another similar jump would obviously drastically change the need for a third pitch.

Prospects with the shortest track records are the hardest to gauge without a minor-league season. Still, McDonald has the tools to be a back-end starter if he can become more comfortable mixing in his changeup and maintain his velocity gains. In 2020, he likely would have returned to Rookie Ball with a chance to pitch at Low-A Salem-Keizer. Without a Low-A level, it will be interesting if he receives an opportunity to make his full-season debut at San Jose or returns to Arizona.