The San Francisco Giants once viewed left-hander Kyle Harrison as the future of their starting rotation. The organization selected him in the third round of the 2020 MLB Draft out of nearby De La Salle High School in Concord.
It only took three years for Harrison to climb up the Giants organization and top prospect lists. The left-hander debuted for the club in 2023 and entered the 2024 season as the No. 23 prospect on MLB Pipeline and No. 24 on Baseball America.
While he wasn’t able to develop any consistency in San Francisco, Harrison has made good on his prospect pedigree. Once the centerpiece in the Rafael Devers blockbuster deal last season, the left-hander has found a new home with the Milwaukee Brewers.
Former Giants Prospect Kyle Harrison Thriving with Brewers
GettyFormer top prospect Kyle Harrison is having the breakout the Giants hoped for, but with another team.
In nine starts this season with Milwaukee, the former Giant has pitched to a 1.77 ERA and a 2.50 FIP over 45.2 innings. His strikeout rate has climbed to a career-high 32.2% to go with a solid 7.7% walk rate. His 1.5 fWAR ranks 15th among MLB starters with at least 40 innings this season.
That comes as a massive improvement for a pitcher who struggled with two previous organizations. In his first three seasons in the majors, Harrison had a career 4.39 ERA and 4.43 FIP in 194.2 innings. When park-adjusting his run prevention metrics, his 108 ERA- and 110 FIP- painted the picture of a top prospect struggling to stick in the big leagues.
However, a couple of minor changes appear to have unlocked the left-hander’s high ceiling. Mark DeRosa broke down those changes on MLB Central.
Mark DeRosa takes a closer look at what has led to Harrison’s breakout with the @Brewers, following his 11-strikeout performance last night against the Cubs.
The first and most obvious change is the move to the first base side of the rubber. That unlocked a better angle for Harrison to locate his slurve, which breaks 10.8 inches to his glove side (in on right-handed hitters, away from left-handed hitters). The results are evident, as he’s limiting opposing hitters to a .116 average and .140 slugging percentage while maintaining a 30.5% whiff rate.
The other change is better fastball command. Harrison’s four-seamer comes in at a flatter angle than most pitchers, allowing him to miss bats at the top of the zone. Since he’s commanding the ball well in that region, it’s yielded whiffs on 33.5% of swings and a 24.0% two-strike putaway rate.
The development of his fastball and slurve combination, something the Giants weren’t quite able to harness, has allowed Harrison to flourish in Milwaukee.
Kyle Harrison’s Success Makes Rafael Devers Trade Look Bad
GettyKyle Harrison’s success with the Brewers adds a new wrinkle to the Rafael Devers trade.
With Harrison thriving with the Brewers, it circles back to whether the Giants gave up on the left-hander too early. You can’t fault Buster Posey for trying to add a big bat to their lineup, and a player like Devers rarely ever becomes available. However, the club remains on the hook for the final $250 million of a $313.5 million extension he signed with Boston, viewed as one of the worst contracts in MLB.
While Devers hit well in his first year with the Giants, he has not been the same in his second. He’s slashed .246/.291/.403 with six home runs and a 93 wRC+.
That’s certainly not the production that Posey and the Giants envisioned when acquiring one of the top left-handed bats. Devers has been consistent at barreling the ball up throughout his tenure with the Red Sox, a potential 30-homer and 100 RBI bat.
Devers’ average exit velocity is down nearly 3 MPH compared to last season. That’s reflected in his barrel rate dropping to 9.2% on the season. It compares well to the rest of the league, ranking in the 59th percentile, but is below his career mark of 12.4%.
However, the slugger may be on a rebound. Over the last 14 days, he’s hit .314 with three home runs. His 168 wRC+ over that stretch leads the club. The Giants need to see this hot streak continue for a longer period if they aim to compete in future seasons.
While the Giants were not able to get the most out of Harrison, they can rest a little easier that the Red Sox did not either.
Giants Pitcher in Rafael Devers Trade Thriving with Brewers