(CBS) Bears backup running back Marion Barber will not play Sunday against the Atlanta Falcons in the season opener.

Barber has been out with a calf injury since the third preseason game at Tennessee. The team has characterized the injury as minor, but the recovery process has been slow.

With Barber out, Kahlil Bell will be the only reserve running back behind starter Matt Forte. The Bears cut running back Chester Taylor last weekend.