49ers lose star Nick Bosa for remainder of 2025 season with torn ACL
Defensive end tears ACL in win over Cardinals; season-ending surgery expected; club targets a 2026 return as it leans on depth to fill the void.
San Francisco 49ers defensive end Nick Bosa will miss the remainder of the 2025 season after tearing his ACL during Sunday’s win over the Arizona Cardinals, multiple outlets reported. ESPN described the tear as clean and said season-ending surgery will be required, with recovery expected to span the offseason and a return targeted for the start of the 2026 campaign. The injury compounds a history of knee problems for Bosa, who previously tore his ACL in Week 2 of the 2020 season against the New York Jets and partially tore the ligament in high school in 2015.
Late in the first quarter of San Francisco's 16-15 victory over the Cardinals, Bosa was rushing Cardinals quarterback Kyler Murray from the left edge when he tangled with left tackle Kelvin Beachum. His knee buckled, and he walked slowly to the sideline with trainers before heading to the locker room and not returning.
There is a public-relations note from coach Kyle Shanahan: initial sideline tests did not indicate an ACL tear, but he cautioned that a serious injury was possible and said the MRI would provide confirmation. Bosa had started the season strong, posting two sacks, four tackles for loss and two forced fumbles in three games.
"Anytime you lose a guy like Nick and his status is unknown, it’s a real buzzkill," All-Pro left tackle Trent Williams told ESPN. "It is cliché to say the next man up, but when you lose a guy like that, you need three or four guys to come fill those shoes."
San Francisco will now lean on its depth, with rookie Mykel Williams, Bryce Huff, Yetur Gross-Matos and Sam Okuayinonu expected to step up in Bosa’s absence. The 49ers’ injury woes extend to the offensive side as well, with tight end George Kittle and quarterback Brock Purdy also dealing with ailments, though neither injury appears season-ending at this stage.
With Bosa out, the 49ers face a rigorous schedule without one of their defining defenders. The organization will rely on younger pass-rushers to sustain a front that has been the bedrock of its defensive identity. Bosa’s absence will force schematic adjustments and elevate the importance of the reserve group as San Francisco considers its long-term outlook for 2025 and the 2026 kickoff.
Bosa’s ACL injury adds to a well-documented pattern of knee issues for the star defender. He previously suffered a torn ACL in 2020 and, as noted, sustained a ligament issue in high school. The club will proceed with the expected surgery and a careful rehab plan, while evaluating how best to preserve the defense’s competitiveness in his absence. The 49ers have historically built a resilient, adaptable rotation on the edge, and they will now rely on that depth more than ever as they work toward a potential return in 2026.
The team and its supporters will be watching closely as more details emerge from medical staff and team officials in the coming days, and the 49ers will begin the path toward evaluating roster options and developing a plan to keep the defense on course without one of its most impactful players.