Why Trevor McDonald is an SF Giants sleeper prospect

After emerging as a standout at Single-A last season, SF Giants pitching prospect Trevor McDonald is looking to take another step forward this year.

The SF Giants have had several top picks from their 2019 draft class fail to live up to expectations over the past few seasons. However, 11th-round pick Trevor McDonald, who the Giants signed away from a South Alabama commitment for $800,000 has quietly begun turning heads in the lower minors. McDonald is currently the 15th-best prospect in the Giants farm system and spoke with Giants Baseball Insider about his 2022 season earlier this offseason. 

McDonald already had a taste of full-season ball in 2021, when he pitched in the final moments of the regular season with San Jose after posting a solid 3.86 ERA and striking out 69 batters in 67.2 innings at the Arizona Complex League. Back in San Jose with a crowded pitching in 2022, McDonald started the season in the bullpen and right away, things already looked different.

McDonald reworked his delivery last winter and credited going back to old pitching drills from his high school days to help him make a seamless adjustment. "I threw a lot of footballs and weighted plyo balls with an over-emphasis on a short arm path to create that muscle memorization and feeling," McDonald said in an interview with Giants Baseball Insider. "Getting the two pieced together really helped me improve a lot [last] year." 

The tweaks that McDonald made were effective right away, with him throwing 66% of his pitches for strikes in his first three months of action out of the bullpen, a far cry from the 57% strike rate he'd posted in his cup of coffee at Single-A the season prior. 

Trevor McDonald's pitching mechanics comparisons pic.twitter.com/qnMdK8NxDe

— Giant Prospective (@giantprospectiv) December 11, 2022

The improved strike-throwing also came with plenty of whiffs. His deep repertoire of pitches all seemed to take a step forward. His four-seam fastball has touched 98 mph, but he mostly relied on a 92-94 mph sinker that has a penchant for inducing weak contact. He also has a slow curveball, changeup, and a pair of sliders: a cutter-like pitch in the high-80s and an offering with more depth that's a couple of ticks slower. The tweaks to his mechanics helped him locate all of his pitches with added deception.

"Getting my arm cleaned up allowed me to be more consistent with all my pitches which allowed me to mix it up more," McDonald said. During the season, he focused on his slider grip, which ended up giving him his two varieties.

With an arsenal as deep as McDonald's, it was only a matter of time until he found his way into the San Jose rotation. After some promotions and injuries, McDonald joined the rotation for the second half. He recorded a 1.88 ERA as a starter.

"I have a routine I like to do but I’m not superstitious about having to go through it," McDonald said about the difference between relief pitching and starting. "If I have all the time I need to get ready before a start, that’s good, but if I have to ramp it up and get going quickly to come out of the pen, that’s fine too. I come in with the same mentality to get guys out."

After joining the rotation, McDonald was promptly promoted to High-A Eugene, where he helped the Emeralds win the Northwest League Championship. McDonald pitched in Game 2 of the series and earned the win, pitching 2.1 innings of two-run ball with a strikeout.

Ever since he was thrust into the starting rotation last July, McDonald saw a big jump in his workload, never dipping below 70 pitches and going over 100 pitches twice. It was a rare occurrence in the farm system as the Giants prioritized limiting the innings for their young arms. But McDonald kept throwing his fastball in the mid-90s and seemed even stronger in September than he looked in May. McDonald credited his workout regiment for helping him maintain his stuff throughout the year.

"Getting after it in the weight room and staying on top of arm care during the season is also one of my top priorities," McDonald said.

With another offseason comes another opportunity to move one step closer to the big leagues, and Trevor McDonald has that ambition. McDonald said, "I’m working on everything. There’s something you can get better at every day and that’s what I plan to do. Staying consistent on those queues that I pick up on (this past season) is my focus." Given how far he has come over the past few years, another big step forward could be on the horizon this season.