Bosa (calf) has been ruled out ahead of Sunday's game against the Cardinals.
Coach Kyle Shanahan said that Bosa is expected to miss "a few weeks" with a calf issue, Matt Barrows of The Athletic reports. It is unclear if Bosa will need to miss the minimum of four games that placement on IR would require. Even if he must miss more than four games, the team may not place the 28-year-old on IR anyway because it has almost reached its limit of eight designated-to-return players.