What happened to Nick Bosa? 49ers dealt major blow as DE goes out with season ending injury

Nick Bosa is another headache for Kyle Shanahan.

The health situation for the San Francisco 49ers was already difficult. This Monday, more terrible news arrived to cloud the franchise's undefeated season. Bosa, who left the game against the Arizona Cardinals due to a knee injury, suffered a torn ACL and will require surgery. He's out for the season.

Nick Bosa's injury is a major blow to the 2025 aspirations for the 49ers. After a difficult year in 2024, the team was clinging to the return of key talent and an easier schedule to return to the playoffs. But injuries continue to affect them: Brock Purdy, George Kittle, Jauan Jennings (and now Bosa) have already missed games.

This is his third knee surgery. In 2020, his second year in the NFL, Bosa also suffered a torn ACL in his left knee after a fantastic rookie season. Although the injury is in his right knee, it's a recurrence: in 2015, still far from the NFL, he also underwent surgery on his right knee to repair a partial ACL tear.

Rookie Mykel Williams and Bryce Huff will be tasked with handling the bulk of pass rushing reps for the team. However, Bosa's impact will be sorely missed. He's one of the league's best edge rushers.

Even after a new knee surgery, 49ers can't release Nick Bosa due to dead cap purposes

Bosa will be 29 when next season starts, and will have undergone surgery on both knees. In 2024, he was clearly not at his best, despite an impactful season.

However, San Francisco has no choice but to keep him on the roster for the upcoming season. His contract holds a huge dead cap if they decide to cut bait with him in 2026 ($75.9 million), making it virtually impossible to move him.

San Francisco can take solace in the fact that, according to reporters, he suffered no damage to his other knee ligaments, which should make for an easy recovery.

Nick Bosa's chances of playing for San Francisco in 2027 are significantly reduced, with a dead cap of "only" $34.2 million if the franchise chooses to cut ties. Although a heavy hit, this would be a possibility if the team decides to go a different route.