Updated

Pittsburgh Steelers running back Le'Veon Bell appears unlikely to be ready for the start of the upcoming regular season due to a foot injury the rookie sustained in the team's last preseason game.

Head coach Mike Tomlin revealed Wednesday that the team is awaiting the results of a second opinion on Bell's ailing right foot, which he hurt in the first quarter of Monday's 24-13 loss to Washington. NFL.com reported that the Steelers are concerned that the 2013 second-round pick may have a Lisfranc injury that could require surgery.

Bell, who was running as Pittsburgh's starting running back in camp, has been ruled out of Saturday's preseason matchup against Kansas City.

"Le'Veon had his MRI on Tuesday, and we are still awaiting final diagnosis and results of a second opinion," said Tomlin. "He will not participate this weekend against the Kansas City Chiefs, and I will provide an update once we have received the official results of his tests over the next couple of days."

If Bell is to miss an extended period, returnees Isaac Redman and Jonathan Dwyer are expected to share carries in the backfield. Dwyer led the Steelers with 623 rushing yards on 156 attempts last season.

The Steelers begin the regular season at home against Tennessee on September 8.