Briggs was ruled out Friday for Sunday's home game against Miami after he missed practice all week.
Linebacker Jonathan Bostic is questionable after missing last week's game with a back injury. Also out Sunday is safety Chris Conte, who has failed to finish four games this season due to concussions and shoulder injuries. Rookie Brock Vereen will start in his place.
The Bears will likely have their starting offensive line back for the first time since the season-opener as left tackle Jermon Bushrod returns from knee and ankle injuries.