Bosa sprained his calf just before Thursday’s practice, and Shanahan confirmed he’ll be out for weeks.
Shanahan guessed the recovery will take roughly a few weeks, according to David Bonilla of 49erswebzone.com.
The 49ers also ruled rookie Romello Height, sidelined by hand surgery, out of Sunday’s clash with the Cardinals, adding to their defensive line woes.
DT C.J. West (knee), DE Sam Okuayinonu (foot) and DT Alfred Collins (patellar tendon) sit on IR, while rookie DT James Thompson Jr. nursed a high‑ankle sprain that will keep him out for weeks.
Losing Bosa felt brutal, Shanahan admitted, noting six of the ten D‑linemen have gone down in two weeks. In my view, the 49ers’ depth will be tested.
Bosa came back from a torn right‑knee ACL, logging 70 snaps across the first two games, after hurting that knee in Week 3 of last season against the Cardinals.
Shanahan wasn’t certain whether the injury involved Bosa’s right calf.
The defender was warming up before the walkthrough when the calf injury occurred.
‘I know he’s bummed, but he’ll be back,’ Shanahan assured.
The club is still weighing a move to injured reserve; only eight players may return this season, and several IR spots are already earmarked for comeback candidates.
He said a handful of guys share the same fate, and with limited IR slots they must guess who’ll be out longer and who could return sooner.
Will the 49ers manage to shuffle their roster in time for the next matchup?