Carimi, the team's starting right tackle, has been out since the second game of the season with a dislocated right knee. Carimi returned briefly to practice, but suffered a setback and underwent an arthroscopic procedure Nov. 11.
Lance Louis moved from right guard to right tackle to replace Carimi and will continue at that position.
"It's disappointing, yes, but he's been out for a while and we've played most of the season without him," coach Lovie Smith said. "Gabe eventually will be a great player for us.
"But right now, I mean, other guys have stepped up and we've moved on."
The Bears have elevated two practice squad players to replace Williams and Carimi: former Montana tackle Levi Horn and former Nebraska guard Ricky Henry.
Also Friday, the Bears announced nickel back D. J. Moore is doubtful for Sunday's game due to an ankle sprain suffered Wednesday. Smith said it's likely Corey Graham will replace Moore, who was fined $15,000 Friday by the NFL for charging into Detroit Lions quarterback Matthew Stafford last Sunday, leading to a scuffle near the Lions sideline. Stafford was fined $7,500 for his part in it.
Moore was not available to comment after Friday's practice due to his injury.
Copyright 2011 by The Associated Press