The Seahawks will host the Bears at Lumen Field Thursday night, a game that was initially going to be started by quarterback Drew Lock, a plan that changed Tuesday when Lock tested positive for COVID-19.

"It came out of nowhere, so obviously he'll miss this game, but he has a chance to get back," Carroll said. "He's got a five-day window that he's got to take care of. It's just unfortunate that it was his turn to start, but we'll figure it out."

Carroll confirmed that Lock's absence means Geno Smith will once again start at quarterback, and that Jacob Eason will also see significant playing time after not playing in Seattle's preseason opener at Pittsburgh.

Asked how Lock was feeling, Carroll said, "He was under the weather yesterday. He barely made it off the practice field, he was just dragging."

Carroll said the plan was to have Lock get in extra work after practice throwing to DK Metcalf, Tyler Lockett Seattle's tight ends, but that plan had to be scrapped when Lock wasn't feeling well. Carroll did not say what the plan will be at quarterback next week.

In injury news, rookie running back Kenneth Walker III won't play Thursday and is, as Carroll explained it, "having a procedure done." Carroll, who a day earlier said Walker was out with a hernia issue, clarified, "This is not a sports hernia, it's something a little bit different. We have a chance to get him back quickly." 

Linebacker Jordyn Brooks, who missed the preseason opener—though it's not clear how much he would have played even if fully healthy—due to a hamstring injury, returned to practice Tuesday and is pushing to get back, but may not play Thursday. 

"He wants to go, we're still talking to him about that," Carroll said, adding that a short week this week followed by a seven-day gap before the next game, means the Seahawks will err on the side of caution when it comes to bringing players back from injuries for a Thursday night game.

"We don't want to rush any of these decisions if we don't have to," Carroll said. 

Jake Curhan, who is competing for the starting job at right tackle, was back at practice after being out with back spasms a day earlier, and is good to go for Thursday night, Carroll said. 

Defensive end L.J. Collier, who has been out since injuring his elbow in Seattle's mock game earlier this month, is "really close" to returning, but won't play Thursday.

"We just think the game came too fast," Carroll said. "Maybe if it was on the weekend, he'd be all right. We'll get him next week."

Cornerback Artie Burns, who has been out with a groin injury for more than a week, "looks pretty good right now and he's coming around," Carroll said. "He's really determined to get back next week. If he doesn't, then it's a big break and he'd certainly be back for the opener, but I'd really like to get it done (next week) and he wants to do the same.

Outside linebacker Aaron Donkor is dealing with what Carroll called "a little hamstring deal" but is holding out hope he can play.

"I talked to him this afternoon, he's dying to get out there and go, but he's questionable to make it," Carroll said.

Carroll was also asked about cornerback Tre Brown, who is still on the physically unable to perform list, the result of the knee injury that cut short his rookie season.

"I saw him running yesterday," Carroll said. "It's controlled, he's not running full speed yet. So he's making progress. I didn't find out today how he came back from yesterday's workout, that's always the important indicator, but he's on the ground running and he's trying to get back."