49ers lose defensive tackle C.J. West to season-ending knee surgery

San Francisco 49ers head coach Kyle Shanahan announced on Tuesday that defensive tackle C.J. West will undergo knee surgery and miss the bulk of the season, adding another major blow to a roster already riddled with injuries ahead of Sunday’s showdown with the Arizona Cardinals.

West, a third‑year starter, has been a key interior presence since he was drafted in 2022. His ability to plug gaps and pressure the quarterback helped the 49ers post a top‑10 defense last year. The loss comes after a spate of setbacks that have already sidelined Nick Bosa, Dee Ford and linebacker Fred Warner for significant stretches. With the defensive line thin, the team’s ability to stop the run and generate pass rush is in serious doubt.

Medical staff confirmed the need for arthroscopic surgery on West’s left knee, a procedure that typically requires six to eight weeks of rehab before a player can return to practice, and even longer to regain game shape. Shanahan said the decision was “unfortunate but necessary” and praised West’s professionalism in handling the news. The coach added that the team will lean on backups Aaron Banks and Isaiah Buggs, while also considering a mid‑season free‑agent signing to shore up the line.

The 49ers now face a critical test against the Cardinals, who rank near the top of the league in rushing yards per game. Defensive coordinator DeMeco Ryans is expected to shuffle personnel and scheme to mask the depth issue, likely increasing blitz packages from the linebackers. A strong performance could keep San Francisco on track for a playoff berth, but continued attrition may force the team to dip into the trade market before the deadline. The next few weeks will determine whether the 49ers can stay competitive despite the mounting injury list.