When it's a bone, it becomes a matter of pain, not so much what the player can do athletically. They'll shoot him up, so he'll have no problems in the first half, however late in the game he'll likely be in some pain.
Believe me, if this was REALLY a problem for Mack, then all these leaks about the injury wouldn't be happening. Maybe they are hoping to get the Pats to change their game plan.
While it might be nice for some fans to think this will be a problem for Atlanta, it is likely it will be as much a factor in the game as Alan Branch's toe and Hightower's shoulder.