The 49ers received devastating news on Monday morning.

Defensive end Nick Bosa, who left Sunday's 16-15 win over the Arizona Cardinals with a right knee injury and did not return, suffered a season-ending torn ACL, ESPN's Adam Schefter reported Monday, citing sources.

Tests today showed that 49ers Pro Bowl DE Nick Bosa suffered a season-ending torn ACL during Sunday’s win over Arizona, sources tell ESPN. It’s a clean tear, but Bosa now will need season-ending surgery. pic.twitter.com/f6xdHY0iVS — Adam Schefter (@AdamSchefter) September 22, 2025

Bosa left the game in the first quarter and immediately went to the blue medical tent, where he eventually reappeared and gave a thumbs-down sign, which was an early indication that the injury could be serious.

Bosa is questionable to retur

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