San Francisco 49ers defensive end Nick Bosa is believed to have a suffered a torn ACL in Sunday's win over the Arizona Cardinals, NFL Network Insider Ian Rapoport reported Monday.

Bosa “gave a thumbs down” after the injury, signaling he sensed the severity of it. An MRI Monday morning showed a “clean, season-ending tear”.

SANTA CLARA — Nick Bosa’s torn ACL was a gut punch to the entire 49ers’ roster. “I’m sick. I’m so sick for him,” linebacker Fred Warner said Wednesday. But the season-ending injury to the Niners’ All-Pro defensive end is also a call to arms for this team’s offense, which has been middling at best this season.

While head coach Kyle Shanahan told reporters after Sunday’s game that San Francisco didn’t think Bosa’s 2025 was over, tests revealed on Monday that Bosa did, in fact, tear his ACL during the Week 3 contest, according to multiple reports. Bosa will now undergo season-ending surgery.

Tearing an ACL is nothing new for Nick Bosa and the San Francisco 49ers. This happened five years ago in 2020, and Bosa was able to bounce back strong the follo

The San Francisco 49ers lost defensive end Nick Bosa for the remainder of the season, but at least they'll get some extra cap space next year.