As he has for the past couple of Wednesdays, coach Lovie Smith put his team through a practice without helmets as part of a late-season plan to save wear on key players already dealing with physical fallout.
Even with the reduced workload, running backs Armando Allen (knee) and Matt Forte (ankle) did not practice, in addition to linebackers Blake Costanzo (calf) and Brian Urlacher (hamstring) and cornerback Charles Tillman (ribs).
The Bears signed former Houston and Miami safety Troy Nolan on Wednesday because of the doubtful situation with Chris Conte (hamstring), who Smith said appears to be headed for a prolonged stretch out of the lineup.
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Tackle Jonathan Scott (hamstring) and defensive tackle Henry Melton (chest) were limited on Wednesday.
Several key Detroit Lions were limping through practice as well, with wide receiver Calvin Johnson (kneeankle), tight end Brandon Pettigrew (ankle), safety Louis Delas (knee) and defensive tackle Sammie Hill (toe) out altogether.
Cornerback Chris Hudson was limited with a hamstring strain.