Amukamara hasn't practiced with the Bears during their light work at Halas Hall this week. Kevin Toliver would likely start in place of Amukamara at cornerback.
The Bears also practiced Tuesday without tight end Ben Braunecker (concussion), receiver Taylor Gabriel (concussion), offensive tackle Bobby Massie (ankle) and linebacker Danny Trevathan (elbow). Defensive lineman Bilal Nichols (knee) was limited.
Formal injury designations for the game Thursday will be released Wednesday. The Bears (6-6) and Cowboys (6-6) kick off at 7:20 p.m. Thursday from Soldier Field.