Stewart injured his knee in the third quarter of the Panthers 37-19 loss to the Pittsburgh Steelers on Sunday.
Carolina is already without starter DeAngelo Williams, who has not played since Week 1 after injuring his thigh. Third-string running back Fozzy Whittaker has a quad injury and did not play against Pittsburgh.
Coach Ron Rivera revealed Monday afternoon that Tolbert won't be available in Week 4. If neither Williams nor Stewart can play Sunday against the Baltimore Ravens, the team may have to rely on undrafted rookie Darrin Reaves, who has spent most of the season on the practice squad or Lache Seastrunk, who was signed to the practice squad before the Week 3 game.
The Charlotte Observer's Jonathan Jones also reported that linebacker Thomas Davis won't practice this week due to an undisclosed injury.
- Scooby Axson and Sarah Barshop