Nick Bosa’s health has been one of the biggest storylines surrounding the San Francisco 49ers this year, and for good reason — the star defensive end tore his ACL in Week 3 of the 2025 season and missed the rest of that campaign.

How the injury happened

Bosa went down during a win over the Arizona Cardinals last September, limping off the field after a third-down pass rush. An MRI confirmed a torn ACL in his right knee — the second serious knee injury of his career, after a similar tear back in 2020. He underwent season-ending surgery shortly after.

A long road back

49ers general manager John Lynch gave positive updates on Bosa’s recovery throughout the offseason, and by early September 2026, Bosa was practicing without restrictions for the first time since the injury. He briefly dealt with tendinitis that slowed him during camp, but returned to practice on September 2 wearing a brace on his surgically repaired knee.

Cleared for the opener

Defensive coordinator Raheem Morris confirmed Bosa would play in the 49ers’ season opener against the Los Angeles Rams in Melbourne, Australia, saying plainly, “He’s going out there.” The return is a significant boost for a defense that recorded just 20 sacks in 2025 — the lowest total in the NFL — largely because of Bosa’s absence.

A five-time Pro Bowler and the 2022 NFL Defensive Player of the Year, Bosa’s return to full health is one of the biggest factors in whether San Francisco’s defense can bounce back to its usual form in 2026.