49ers’ star defensive lineman Nick Bosa out for season with torn ACL

By Carlos E. Castañeda

San Francisco 49ers star defensive lineman Nick Bosa will miss the rest of the season with a torn anterior cruciate ligament, the team confirmed Monday.

Head coach Kyle Shanahan told reporters at a conference call that Bosa will undergo season-ending surgery on his right knee.

“I talked to Nick last night. You know, it wasn’t confirmed until this morning,” Shanahan said. “I haven’t been able to see him yet today, but talked to him last night, he had a pretty good idea of what we were going to find out today.”     

Bosa injured himself in the 1st half of the 49ers’ victory against the Arizona Cardinals on Sunday. Television coverage of the game showed Bosa on the ground on the sideline after his injury, and later gesturing toward the stands after a visit to the medical tent with a “thumbs down” as he limped toward the locker room.

Shanahan originally voiced optimism about the severity of Bosa’s injury in remarks to reporters after the game, but said more tests were needed to confirm the extent of the injury.  

It’s the second time Bosa has suffered a season-ending knee injury. In the 2020 season, Bosa suffered a torn ACL in Week 2 and was placed on injured reserve.

Bosa, who won multiple honors at Ohio State before forgoing his senior year to enter the 2019 NFL Draft, is a five-time Pro Bowler and the 2022 NFL Defensive Player of the Year. He was also voted First-team All-Pro in 2022 and was the 2019 Defensive Rookie of the Year.

He is considered one of the best defensive players in the league and is one of the highest-paid defenders in the NFL after signing a record-setting five-year $170 million contract extension with the 49ers in 2023.

Bosa had a quarterback sack in each of the 49ers’ first two games, including a strip sack and fumble recovery during the season opener against the Seattle Seahawks that sealed the win in the final seconds.

“You don’t just replace a guy like Nick,” Shanahan said. “Everyone has to get better.”    

The Niners have been missing several of their biggest stars with tight end George Kittle on injured reserve after hurting his hamstring in the season opener, No. 1 receiver Brandon Aiyuk on the physically unable to perform list recovering from knee surgery, and quarterback Brock Purdy missing two games with a toe injury.