The Bears announced Wednesday that they have signed OG-C Edwin Williams to a two-year contract extension, locking him up through the 2013 season.
The Bears could catch a break Sunday if DT Richard Seymour is limited by a knee injury.
Chris Williams' season-ending injury leads to the latest in the steady flow of lineup changes that O-line coach Mike Tice has managed well since the start of last season.
The Chargers' strategy Sunday will likely include putting eight men in the box often to try to stop RB Matt Forté.
OG-C Edwin Williams was elevated from the Bears' practice squad to their 53-man roster Monday. He takes the spot of OG Johan Asiata, who was released.
The Bears added OL Edwin Williams on Wednesday to add depth to their offensive line and released RB Brandon Minor.
Washington released four players Tuesday, including a rookie whom they acquired a day earlier.