"He didn't think it was a big deal," Spagnuolo said Monday of Jackson's reaction to the injury. "He kept playing. ... He's going to be sore. Hopefully, he'll be able to play this week. We'll know more after he gets through it. ... He's just a warrior. He goes out and plays, and we find out later on there's a crack in there."
Also on the sideline Wednesday were cornerback Justin King (hamstring), safeties James Butler (knee) and Darian Stewart (hamstring), and defensive tackles Fred Robbins (toe) and Darell Scott (ankle).
The Associated Press contributed to this report.