The San Francisco Giants will be without their home run leader for the crucial final week of the 2021 regular season. First baseman Brandon Belt has a broken left thumb, an x-ray revealed Monday, according to The Athletic's Andrew Baggarly. The Giants did not provide a timetable for his return.

Belt suffered the injury when he squared around to bunt against the shift against Rockies lefty Lucas Gilbreath in the seventh inning Sunday. He remained in the game to run the bases, then was removed after the inning. Here's the video:

"Not at all," Giants manager Gabe Kapler told reporters, including's Maria Guardado, when asked whether he had a problem with Belt trying to bunt. "He knows when the best way for him to get on base is to put a bunt down. ... Not surprised. I thought it was a smart play against a tough lefty late in the game."  

Belt, 33, is one of several veteran Giants having a resurgent season. He owns a .274/.378/.597 batting line with a team-leading (and career-high) 29 home runs. Belt has been especially hot the last few weeks, hitting .349/.451/.721 with nine home runs in September. Now he'll miss an unknown length of time, potentially including postseason games.

Replacing Belt's offense will be close to impossible. Replacing him at first base won't be too difficult though. The sneaky great LaMonte Wade Jr. played the position when Belt was sidelined with oblique and knee problems earlier this year. Wilmer Flores can play first base as well, ditto for Kris Bryant. San Francisco is not short on first-base capable players.

Of course, losing one of your best hitters (and your best power hitter) when you're fighting for a division title is a devastating blow. The Giants are two games up on the rival Dodgers with six games to play. It is entirely possible the NL West race will go down to the final day of the season this Sunday.

The Giants have already clinched a postseason spot. They close out the regular season this week with a six-game homestand against the Diamondbacks and Padres. San Francisco is an MLB best 102-54 this year.