The 49ers also will be missing star defensive end Nick Bosa, who is out after leaving last week’s game in the second half with injuries to his left hip and oblique. Left tackle Trent Williams is questionable with an ankle injury and will be a game-time decision.
San Francisco struggled on defense without Bosa last week and now will go the entire game this week without two of the team’s most important players.
The Niners (5–5) are currently in a three-way tie for second in the NFC West, a game behind first-place Arizona, and have little margin for error if they want to get back to the playoffs after making it to the Super Bowl last season.
“I know it’s disappointing,” Shanahan said. “We knew there was a chance for Nick. I think the guys were a little surprised with Brock yesterday, but we addressed all that today. We’re going to have 48 guys in uniform. I know our guys believe in themselves. I believe in them. We’re missing two good players, definitely. But we got a lot of good players out there. So by no means do we not have a chance to win.”
This will be the first time Purdy has missed a start because of an injury since taking over as the 49ers’ quarterback in December 2022. Brandon Allen will start in his place.
Purdy has completed 66% of his passes this season for 2,613 yards, 13 TDs, eight interceptions and a 95.9 passer rating that is down significantly from his league-leading mark of 113 in 2023.