The biggest component of Seattle's run defence also is a rather large question mark for the game today in Chicago.
But defensive end Red Bryant isn't the only Seahawk whose status is in doubt.
Cornerback Marcus Tru-fant has been diagnosed with a hamstring injury that leaves him unlikely to play while receiver Sidney Rice's calf muscle tightened up during practice Friday, forcing him to sit out the final third of the workout. He is listed as questionable.
"We've just got to see what happens," coach Pete Carroll said of Rice. "We think he's OK."
The Seahawks have been one of the NFL's healthiest teams this season. Receiver Ben Obomanu is the only player who has been placed on injured reserve since the regular season began. This week, Seattle faces more uncertainty due to injury than in any other game this season.
The Seahawks have three starters listed as questionable: Rice, Bryant and line-backer Leroy Hill. Trufant is doubtful after he was diagnosed with a hamstring injury after practice Thursday.
"We're really surprised that that popped up," Carroll said. "It's going to be hard for him to get back from that."
Cornerback Walter Thurmond will be active for the first time this season, returning from a broken leg he suffered last season and reinjured in March. Thurmond is likely to take Tru-fant's spot when the team uses its nickel formations that call for five defensive backs.
Of the three starters listed as questionable, Hill has the best chance to play. He was able to finish the game last Sunday in Miami despite suffering an ankle injury, and while he didn't participate in practice this past week, he did run at full speed Friday and was able to change directions.
"He had a legitimate workout," Carroll said. "We'll check him out [Saturday] and again all the way up to game day."
Replacing Bryant is a little tricky.
A defensive end, he is critical to the team's base defence. While he hasn't missed a game since 2010, the sore foot has bothered him for the past month.
The Seahawks could move Alan Branch from defensive tackle to Bryant's position at end. Branch has a similar build as Bryant, and could fill that role. Seattle also could insert Jason Jones as the starter at end, and while he's not nearly as heavy as Bryant, he does have more pass-rush ability.
Carroll hadn't given up the possibility Bryant might be available, though, even after Bryant missed practice all three days this week.
"We're going to take him all the way up to game time," Carroll said. "He's dying to play."
The Bears have their own question marks as they will be without their two starting guards last week as Lance Louis was placed on injured reserve with a knee injury while Chris Spencer - a former Seahawk - already has been declared out.
The Bears also will be missing return specialist Devin Hester, who is out with a concussion, while receiver Alshon Jeffery is doubtful because of a knee injury.
