When the San Francisco Giants pulled off the blockbuster deal for slugger Rafael Devers, the focus was obvious: power, star power, and a massive bat arriving in the Bay Area. But buried inside that headline-making trade was a young pitcher the Giants had once believed could anchor their future.
Now, that pitcher—Kyle Harrison—may be on the verge of making the Giants regret letting him go.
The left-handed flamethrower, once one of San Francisco’s most intriguing pitching prospects, has landed with the Milwaukee Brewers after a whirlwind journey through one of baseball’s strangest trade chains. And early signs suggest something big could be brewing.
Harrison was originally sent to the Boston Red Sox as part of the trade that brought Devers to San Francisco. But in a surprising twist, Boston quickly moved him again in a six-player deal with Milwaukee, effectively flipping one of the key pieces they had just received.
The result? The Brewers may now be the unexpected winners of the entire sequence.
And Harrison is already showing flashes of why.
This week, the San Jose native made his debut appearance with Milwaukee during an exhibition matchup against Team Great Britain, a tune-up game tied to preparations for the World Baseball Classic.
The outing was short—but eye-opening.
Harrison delivered three scoreless innings, allowing only two hits and one walk while striking out two batters. For a pitcher still settling into a new organization, the performance was exactly the kind of start that gets coaches and scouts leaning forward.
But the real headline wasn’t just the stat line.
It was a brand-new pitch.
Harrison unveiled a developing changeup, a weapon he has reportedly been refining as he looks to evolve beyond the raw fastball dominance that defined his early career.
For Giants fans who followed his rise through the farm system, that fastball was always the story.
When Harrison’s velocity climbed into the mid-90s, hitters struggled to keep up. His deceptive delivery and ability to attack the top of the strike zone made the pitch explosive.
But when the velocity dipped closer to 90 mph, the results were far less intimidating.
That inconsistency often determined whether Harrison looked like a future star—or just another arm trying to survive at the big-league level.
Now, the addition of a reliable changeup could completely change that equation.
Baseball history has shown how devastating that combination can be. Giants legend Tim Lincecum famously dominated hitters for years using the exact formula: a mid-90s fastball paired with a devastating changeup that kept batters guessing.
If Harrison’s new pitch develops into something similar—even remotely—it could transform him from a promising arm into a legitimate major-league starter.
And the Brewers are watching closely.
Last season offered only a small glimpse of what Harrison might become. While with Boston, he posted a 3.00 ERA across 12 innings, a limited but encouraging sample.
His earlier years with San Francisco between 2023 and 2025 produced more mixed results, leaving many analysts unsure whether he would fully break through.
But pitchers often need time—and the right environment—to unlock their best version.
Milwaukee might be exactly that place.
If Harrison takes the next step this season and becomes a reliable rotation piece, the story surrounding the Devers trade could take on a new layer of intrigue.
Because while the Giants secured a superstar hitter…
They may have also watched a future pitching star walk away.
And if Harrison’s breakout truly arrives in Milwaukee, the phrase “the one that got away” might start echoing loudly in San Francisco.