After kick returner/receiver Devin Hester was lost with a concussion, the Bears lost arguably their best offensive lineman this season against the Minnesota Vikings on Sunday.
Right guard Lance Louis suffered a left knee injury early in the third quarter and was ruled out for the remainder of the game.
Louis, who has started every game this season at right guard, was hurt when hit hard by Vikings defensive end Jared Allen during cornerback Antoine Winfield's interception return. Louis was replaced by Gabe Carimi.
Louis' injury comes at very tough time for the Bears.
After a brutal outing in San Francisco, major changes were made to the offensive line as Jonathan Scott replaced Carimi at right tackle and Chris Spencer took over for Chilo Rachal at left guard.
Rachal abruptly left the team and won't play for the Bears again this season. Spencer, meanwhile, suffered a knee injury and missed portions of the game Sunday as Edwin Williams took his spot.