SANTA CLARA — [Nick Bosa’s season](https://www.mercurynews.com/2026/09/24/49ers-nick-bosa-mike-evans-remain-out-of-practice-in-week-3/) could be on hold for multiple games because of a calf injury he sustained this week, ESPN reported Friday morning.
The [49ers listed Bosa](https://www.mercurynews.com/2026/09/20/49ers-nick-bosa-defense-dolphins-romello-height/) as a non-participant in practices Wednesday and Thursday, but he’s often done side-field conditioning over the past two months, and they added the calf issue to Thursday’s participation report.
Bosa has no sacks two games into his comeback from last season’s torn anterior cruciate ligament in his right knee, which flared up early in training camp and kept him out of practice nearly a month.
The 49ers, ESPN’s Adam Schefter reported, are unlikely to add Bosa to an Injured Reserve roster that’s already taken on eight players since the initial 53-man roster was set. NFL rules allow eight such players to return from IR.
Bosa, who turns 29 on Oct. 23, is a five-time Pro Bowler who won 2019 NFL Defensive Rookie of the Year and 2022 NFL Defensive Player of the Year honors. He missed 14 games in both the 2020 and 2025 seasons because of ACL tears, to different knees.
The 49ers’ defensive line has been decimated by injuries, some of which have occurred in practice, including those to Sam Okuayinonu (foot) and Alfred Collins (knee) in the week leading up to the season opener. Casualties from that unit after Sunday’s home-opening win over Arizona were C.J. West (bone chip in knee; put on Injured Reserve on Wednesday), Romello Height (fractured hand) and James Thompson Jr. (high-ankle sprain).
Presuming Bosa and Height are out, Sunday’s starters at defensive end could be Keion White and Khalid Kareem or Ogbo Okoronkwo. At defensive tackle, Osa Odighizuwa and rookie Gracen Halton have impressed, but their styles overlap and the 49ers likely need a heftier nose tackle next to Odighizuwa in the starting lineup so that could be newcomer Naquan Jones or veteran Kevin Givens.
“Our scouting staff has done a nice job throughout the year, knowing that’s a spot we need depth. We’re equipped for it,” general manager John Lynch said Thursday morning on KNBR 680-AM about the defensive line. “There’s opportunities for guys to go play. You hate to see guys go out. But you equip yourself for it. We kind of had that luxury. We are deep there.”
Coach Kyle Shanahan is expected to address the media and deliver game-day status projections about 1:35 p.m., after an hour-long walk-through.