SAN FRANCISCO -- The Giants have spent all season calling up rookies to bolster their lineup and bullpen. Now they're doing it for the rotation, and the latest addition might end up becoming the best of them all.
Kyle Harrison, the organization's top prospect, will make his MLB debut Tuesday night in Philadelphia, manager Gabe Kapler confirmed Sunday after the Giants' 4-3 win over the Atlanta Braves.
The news was first reported Sunday morning by Robert Murray of FanSided, and sources confirmed to NBC Sports Bay Area before the game. Harrison, 22, is one of the best pitching prospects in the minors and the most highly touted Giants pitcher to make his debut since Madison Bumgarner in 2009.
"Last couple of outings, I think he's taken some real steps forward," Kapler said Sunday. "I think he's ready to help us win baseball games. That's like the most important thing. ... He's just ready for the opportunity."
Kapler declined to offer any clarity on Harrison before the game, and the Giants officially listed TBA, TBA and Alex Cobb as their three pitchers for the series against the Phillies earlier Sunday. There wasn't much mystery by the end of the day, though, as Harrison was scratched from his start in Triple-A.
Harrison is a former De La Salle (Concord) star who was selected in the third round of the 2020 MLB Draft. He was viewed as having a strong commitment to UCLA, but the Giants moved bonus money around to sign Harrison, and he has been on the fast track ever since.
Harrison posted a 3.19 ERA in Low-A in 2021 with 157 strikeouts in 98 2/3 innings. A year later, he struck out 186 batters in 113 innings with a 2.71 ERA across High-A and Double-A. The Giants started Harrison in Triple-A this year, and while the ERA (4.66) is high in a hitter-friendly league, he has 105 strikeouts in 65 2/3 innings.
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The lefty has a mid-to-upper 90s fastball and two variations of his slider. He has late life on his fastball and hides all his pitches well, and hitters have generally had an extremely difficult time squaring him up.
The only thing that held Harrison back this long was command. He has walked 48 batters this season, and because he has had such long innings, he has completed five innings just once. Harrison took a step forward this month, though, pounding the zone in his last two starts in Triple-A.
"Very [excited]," Kapler said about Harrison's upcoming debut. "Just as a fan watching him come up through the ranks for us, seeing some struggles in spring training, watching almost all of his outings on video, communicating with our coaches. He's a great guy with an incredible work ethic that wants it really bad.
"His moment has come. Of course, I'm excited for him and us."
The Giants believe he's ready, and they have for some time. Harrison was poised for a July call-up before a hamstring strain put him on the IL, so his pitch count won’t be very high in his debut. The Giants desperately need a boost though.
They have been using just two actual starters for several weeks now, and one of their most reliable “bulk innings” guys -- Ross Stripling -- went on the IL on Saturday. The Giants have said Harrison will arrive as a starter, and while he might not go deep into the game Tuesday, it will be a huge moment for an organization that expects Logan Webb and Harrison to lead the rotation for years to come.