"I wish I had the time to go into everything Mike does, but I really don't, to be truthful," Bears coach Lovie Smith said. "He'll be the quarterback for the (secondary) to get the guys in the right coverage from time to time. He's a run-support guy. He blitzes. There's quite a bit that he does at the safety position in general."
Even after missing last week's game, Brown is fourth on the team with 89 tackles and third with 3 interceptions.
The defense will also likely be without another starter. SLB Hunter Hillenmeyer became an observer in practice this week because of a fractured thumb. He played with a cast against the Steelers, but his effectiveness was limited because of the injury.
Leon Joe is expected to get his first career start. While he's more athletic than Hillenmeyer, his inexperience could be exploited going up against Pro Bowl TE Alge Crumpler, who is Atlanta's leading receiver. He has 56 catches for 779 yards and 5 touchdowns.
After practicing on Wednesday, G Terrence Metcalf sat out on Thursday and Friday. Even though he's still listed as questionable, it appears that Roberto Garza could get a second straight start because Metcalf's shoulder injury hasn't healed.
Garza's sixth start of the season would be up against his former teammates, but he was apprehensive to talk about how he left Atlanta calling it "just another game".
Cedric Benson will miss his fifth consecutive game as he rehabs from an MCL strain. He did some light work throughout the week, but the depth at running back allows the Bears not to rush Benson back onto the field.