According to Ed Bouchette of the Pittsburgh-Post Gazette, the rookie's injury isn't as serious as his teammate Matt Spaeth's Lisfranc injury, suffered earlier this season.
ESPN points out that Bell won't need surgery to recover. However, his sprain can still be a hindrance for the running back and could possibly hurt the player's opener status for the season.
If the injury permits it, Bell is expected to star for the Steelers in the upcoming season. If he's unable to do so, Pittsburgh might use a combination of Isaac Redman and Jonathan Dwyer to take on the role.
Bell got injured during Monday night's preseason game against the Washington Redskins. He attempted to stay in the game and carried the ball four times for nine yards before leaving the game with what was initially diagnosed as a mid-foot sprain.