Sources - 49ers' Nick Bosa has torn ACL, done for season - ESPN

SANTA CLARA, Calif. — The San Francisco 49ers' worst fears were confirmed Monday when tests showed star defensive end Nick Bosa suffered a torn ACL in his right knee, sources told ESPN's Adam Schefter.

The tear is clean, but Bosa will still require season-ending surgery, sources told ESPN.

For Bosa, this is the second season-ending ACL injury of his career. He tore the ACL in his left knee in a Week 2 win against the New York Jets in 2020. He also had a partially torn right ACL when he was a senior in high school (2015).

Bosa left Sunday's 16-15 win against the Arizona Cardinals with about a minute left in the first quarter, went to the locker room and did not return. After the game, coach Kyle Shanahan said the initial test of the ACL on the sideline hadn't shown a tear but cautioned that Bosa and the team were still concerned about the possibility of a serious knee injury.

«There is concern because of how he feels,» Shanahan said Sunday night. «They do the test and stuff on the sideline and usually they say whether he definitely did or not, and they didn't say that. But we are concerned with that [a tear]. Keeping our fingers crossed for the MRI.»

The results of that MRI on Monday showed Bosa's initial feelings were correct. On the play in which he was hurt, Bosa was rushing Cardinals quarterback Kyler Murray from the left side and engaged with left tackle Kelvin Beachum when Cardinals guard Evan Brown came over for the double team and knocked Bosa to the ground.

Bosa's right knee appeared to bend awkwardly as he went down and Murray's pass fell incomplete. Bosa walked slowly to the sideline, where the Niners' training staff began working on him as he laid on his back.

After a few moments, Bosa walked to the medical