Panthers' Mike Tolbert out

CHARLOTTE, N.C. -- The Carolina Panthers will be without running back Mike Tolbert, and likely running back Jonathan Stewart and linebacker Thomas Davis, for Sunday's game against the Baltimore Ravens.

All three were injured in Sunday night's 37-19 loss to the Pittsburgh Steelers.

Tolbert suffered a hairline fracture in his right leg and will miss the 1 p.m. ET game in Baltimore. Stewart suffered a severely sprained right knee and will be re-evaluated Friday.

Coach Ron Rivera was vague on Davis' injury, saying the weakside linebacker was extremely sore and would be re-evaluated Friday as well. Rivera said the injury was not connected to the right knee that has undergone three ACL surgeries.

Davis and Stewart will not practice Wednesday and Thursday, usually a sign they will not play.

Rivera was optimistic that running back DeAngelo Williams would return after missing the past two games with a hamstring injury. He said the team's all-time leading rusher was close to being ready last week but was held out.

The Panthers signed running back Darrin Reaves from the practice squad Saturday with Williams and Fozzy Whittaker (quad) out. Rivera said the team will have to evaluate whether another player is signed for depth.

Carolina rushed for only 42 yards on 10 carries against a Pittsburgh defense that had allowed 348 yards rushing in the first two games.

Quarterback Cam Newton, who has been a big part of the Panthers' rushing offense the past three years, had a career-low two carries for seven yards.

Newton underwent left ankle surgery in March and suffered fractured ribs during the preseason that forced him to miss the opener at Tampa Bay.

"We know that he was a big part of what we do," Rivera said of Newton, who led all quarterbacks in rushing yards and touchdowns the past three years. "The thing that this shows us is we can't rely on him all the time.

"So now we've got to find other answers and ways to do that. I know the coaching staff will be working on that."