Bears linebacker Pisa Tinoisamoa has to decide whether to have season-ending surgery after suffering articulating cartilage damage in his right knee, according to a league source.
Tinoisamoa suffered the injury while planting in coverage during Sunday's 21-14 loss in Atlanta.
He had an MRI on Monday to determine the severity of the injury.
The veteran ruptured the posterior cruciate ligament in the same knee during the season opener in Green Bay. The latest injury could have a significant impact on the linebacker corps, with Brian Urlacher already out following season-ending wrist surgery and Hunter Hillenmeyer still recovering from a cracked rib.
Bears coach Lovie Smith said Monday there were no plans to add another body at linebacker.