The 49ers placed starting defensive tackle Tank Carradine on injured reserve Monday with a high ankle sprain suffered Thursday in a loss to the Rams.
Carradine is a likely candidate for short-term IR, meaning he could return this season. But in such a case, he would have to be out for the next eight weeks. Carradine, 27, has seven tackles this season and one the 49ers’ three sacks.
With Carradine out, rookie Solomon Thomas is expected to assume his starting spot. Thomas has played 128 snaps this season; Carradine has 81.
The 49ers filled Carradine’s roster spot by signing inside linebacker Mark Nzeocha off the Cowboys’ practice squad.