SAN FRANCISCO — The 3-0 win over the Milwaukee Brewers on Monday night was one of the cleanest of the 2026 MLB season for the Giants. They gave up just three hits, getting a strong start from Tyler Mahle and some of their best work from the bullpen. The defense made some big plays, and they stole a season-high three bases. They also got a clutch homer from a young outfielder. 

But Tony Vitello couldn’t smile much when he sat down behind the podium. Vitello lost one of his best players early in the game, and the Giants are unsure when they’ll get him back.

Casey Schmitt made an aggressive turn around first in the second inning and injured his left knee as he put the brakes on. The breakout star of this season, Schmitt limped off the field and needed help getting down the dugout steps. 

The Giants are calling it knee discomfort for now, but Schmitt will get an MRI on Tuesday to determine the extent of the injury. Vitello didn’t offer a lot of clarity, saying at first that Schmitt wouldn’t play Tuesday, and then later mentioning that he was “probably going to miss some significant time.”

Whether that’s weeks or months isn’t known, but regardless, it’s a big blow. Schmitt has hit in the heart of the lineup most of the season, and his 21 homers are a career-high and second on the team to Rafael Devers. The single that led to the injury raised his OPS to .784.

The first move for the Giants will be a complicated one. Every healthy position player on the 40-man roster is already on the active roster, and Vitello said that Matt Chapman would not be rushed back. Before the game, Vitello said Chapman’s return from an abdominal strain was likely to come this weekend at Petco Park. None of the other injured Giants are close enough to return to the roster Tuesday. 

Parks Harber is now in Triple-A, although he has only been there for a few games and the Giants might not want to add him to the 40-man when Chapman will be back so soon. They also could go with a stopgap option like Osleivis Basabe to add infield depth. They have two open 40-man roster spots, so that part won’t require letting go of someone else.

If Schmitt does miss serious time, the Giants will have an opening elsewhere on the dirt even after Chapman returns. The assumption for weeks has been that Schmitt would start at second base the rest of the year after a trade of Luis Arraez, but that might no longer be an option.

Christian Koss and Jesús Rodríguez would be next up on the active roster, with Nate Furman in Triple-A. The Giants also could give a shot to Jonah Cox, an outfielder who looked like a natural when they put him at second base last month. 

They hope that none of the longer-term questions are even necessary. Schmitt’s injury looked scary, but they’re hoping for the best. He has been perhaps their best story this season, and he looks like a big part of the future. 

“He’s a unique personality, but he’s definitely got a level of toughness to him,” Vitello said. “He was really struggling even just to move around there with (Dave Groeschner) checking on him. The first thing is obviously you’ve got to make a change, and second of all, your heart has got to go out to him a little bit and you hope for the best.”

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