Former SF Giants top prospect thriving in Milwaukee's pitching factory

Through two starts with the Milwaukee Brewers former SF Giants top prospect Kyle Harrison is 1-0 with a 2.61 ERA, allowing three runs on seven hits with 14 strikeouts in 10 innings pitched.

The former top SF Giants prospect was a part of the blockbuster trade that sent Harrison, Jordan Hicks, James Tibbs III and Jose Bello to the Boston Red Sox in exchange for Rafael Devers. Only Bello remains in the Red Sox organization now almost a year later.

Kyle Harrison looks really strong with Brewers so far

Harrison was traded to the Milwaukee Brewers from the Red Sox during the offseason. This was arguably the best landing spot for Harrison who was once a highly touted left handed pitching prospect for San Francisco.

Milwaukee is known for having very good pitching development and has produced some of the leagues most dominant pitchers. Including Freddy Peralta, Jacob Misiorowski, Corbin Burnes, Brandon Woodruff (when healthy), and Abner Uribe just to name a few. It stands to reason that Milwaukee's coaches would be able to turn around the trajectory of Harrison's career.

The left-hander only pitched in three games for the Red Sox last year posting a 3.00 ERA over 12 innings. In the eight games he pitched for the Giants in 2025 before the trade Harrison struggled with a 4.56 ERA over 23.2 innings pitched although he did get his velocity back.

In a change from the beginning of his career, Harrison has shifted away from a pitching arsenal almost entirely revolving around his four-seam fastball, and has added a cutter and a changeup. While Harrison still relies heavily on his fastball, he has started to incorporate his slurve more which he increased the break on to 10 inches, two more than the start of his career.

Through two starts this season Harrison has posted an elite chase rate ranking in the 83rd percentile, and 75th percentile of overall pitching run value. His off-speed stuff has been his weakest asset which explains why he employs it the least of his whole arsenal. He has also found about two extra ticks on his fastball since making his MLB debut.

Harrison said he has been less emotional on the mound in the last two years, which is the main difference he could identify when asked about what is different from his rookie season with the Giants.

It seems in addition to getting his emotions in check, the big fix for Harrison has been getting his walks under control as he is issuing far fewer free passes. Now he boasts an elite K/BB ratio with a 4.67 through two starts in 2026.

While it is too early in the season to make blanket statements, it does seem that Milwaukee's pitching coaches have found the fix for Harrison as his career seems to be taking an upward trend. He may just be the next elite arm they churn out of their pitching factory. If he does find success, there will inevitably be some who question the wisdom of the Devers trade while also questioning why the Giants were unable to unlock his potential.