Arizona Cardinals v San Francisco 49ers
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San Francisco 49ers star pass rusher Nick Bosa will miss the remainder of the 2025 season after tests indicated a torn ACL suffered in Sunday's Week 3 game vs. the Arizona Cardinals, according to multiple reports. 49ers coach Kyle Shanahan expressed some optimism after the game about the injury, but an MRI reportedly showed that Bosa will need surgery. 

This is the second ACL injury of Bosa's pro career. In 2020, he missed most of the season with a torn ACL in his left knee. 

The Fox broadcast showed trainers attending to Bosa as he laid down on the sideline before moving to the blue medical tent. Cameras also captured images of Bosa giving someone in the crowd a thumbs down before walking to the locker room with trainers.

The 49ers are off to a 3-0 start to the season despite playing the last two games without starting quarterback Brock Purdy, and San Francisco will now have to navigate the remainder of the 2025 season without their top edge rusher. 

James Conner injury: Cardinals RB out for season after being carted from field vs. 49ers
Zachary Pereles
James Conner injury: Cardinals RB out for season after being carted from field vs. 49ers

Bosa recorded a sack in each of the 49ers' first two games of the season to go along with 15 combined tackles and one forced fumble. He recorded one tackle vs. the Cardinals before exiting the contest. The No. 2 overall pick in the 2019 NFL Draft is one of the best defensive ends in the NFL with 64.5 sacks to go along with 91 tackles for loss in 84 career games played. Bosa led the NFL with 21 tackles for loss in 2021, then came right back the next season and led the league in sacks with 18.5 in 2022.

Injuries have accumulated quickly for the 49ers. In addition to Bosa and Purdy, star tight end George Kittle (hamstring), wide receiver Jauan Jennings (shoulder, ankle) and left guard Ben Bartch (ankle) have been hampered by injuries.