Newton aggravated his sprained left foot during the team's loss to the Tampa Bay Buccaneers on Sept. 12. According to ESPN, he was relegated to working inside with the training staff and went to meetings wearing a walking boot.
"The thing that we have to do is go forward. There's nothing we can do about that," Panthers head coach Ron Rivera told the team's official website. "The injury is what the injury is. It's a sore foot and he's struggling with it. It was re-aggravated Thursday night and now we've had to go forward.
"Now we've got an opportunity to use Kyle Allen and see what Kyle is all about."
This will be Newton's seventh missed start since he made his NFL debut in 2011 against the Cardinals. It remains unclear if the injury could force the quarterback to miss multiple games.
Panthers backup quarterback Kyle Allen will make his second career start Sunday. During last year's regular-season finale, the then-undrafted rookie out of Houston led Carolina to a win over the New Orleans Saints while Newton sat out with an injured shoulder.
Allen completed 16-of-27 passes for 228 yards and two touchdowns against the Saints.
In two games this season, Newton has completed 50-of-89 throws for 572 yards with one interception.