Cornerback Ahkello Witherspoon will miss “at least a month” with a foot sprain, 49ers coach Kyle Shanahan said Monday.
Mike Maiocco of NBCSportsBayArea.com reports Witherspoon is seeking a second opinion from a foot specialist.
Shanahan said Emmanuel Moseley is in line to replace Witherspoon, but Jason Verrett and others will compete for the starting job.
The 49ers have a bye this week.
Witherspoon was carted off in the fourth quarter. Moseley played seven defensive snaps and Verrett four against the Steelers, with Verrett drawing a 32-yard pass interference penalty.
Shanahan said running back Tevin Coleman has a good chance to be back next week. Coleman played 18 snaps in the season opener against the Bucs before being knocked out by a high ankle sprain.