The Chicago Bears will turn to veteran quarterback Nick Foles on Sunday against the Seattle Seahawks because of injuries to starter Justin Fields and backup Andy Dalton, coach Matt Nagy said Friday.

Fields suffered an ankle injury during Monday's 17-9 loss to the Minnesota Vikings. Dalton has been dealing with a groin injury that flared up after he returned this week from the COVID-19 list.

Foles, whom the Bears acquired last season to compete with former starter Mitch Trubisky, has not played this season. Fields finished Monday night's game and was a limited participant in practice Wednesday, but he did not practice Thursday or Friday.

Nagy said the injury hasn't gotten worse, but that the team is trying to gauge "where the pain level is" and did not rule out using Fields as Foles' backup on Sunday. The Bears' only other quarterback is rookie Ryan Willis, who signed to the practice squad Dec. 18.

"We have to balance where we're at with what Ryan could do just getting here recently," Nagy said. "He's literally learning the playbook and what to do. It would probably be more of an emergency situation, and we just have to see where Justin's at percentage-wise, where it doesn't risk his health but he's able to help us. If that's not the best thing to do, trust me, we're going to go ahead and go with Ryan."

Fields, the Bears' No. 1 draft choice last spring, missed two games earlier this season because of cracked ribs. In 12 games this season, he has completed 58.9% of his passes for 1,870 yards, seven touchdowns and 10 interceptions. He has fumbled an NFL-high 12 times and has a 25.1 total quarterback rating, the second worst in the league among qualified quarterbacks.