Newton added that head coach Ron Rivera "assured there is no concern and that his quarterback is 'ready to roll,'" however.
"The only reason he's listed as questionable is because that's what the form says," Rivera said, per Newton. "I'm telling you guys I believe the guy is ready to roll. I really do mean it. I'm pretty confident in his abilities and hopefully things will fall into place nicely for us on Sunday."
Rivera essentially reiterated the comments he made earlier in the week on Newton.
"I think he's ready. I do," he said, per Marc Sessler of NFL.com. "You wish he'd had a few more snaps and played a little bit earlier in the preseason so we'd have more to go on. But what we saw, we liked. We liked how everything seems to be meshing together as an offense and we'll see how it goes as we continue to work this week."
Newton, 28, had shoulder surgery in late March and missed much of the preseason, throwing just two passes (one for a touchdown) in the team's third preseason game.
The 2015 NFL MVP remains the team's most important player and, with weapons added like rookies Christian McCaffrey and Curtis Samuel to pair with Kelvin Benjamin and Greg Olsen, is primed for a big season after a down year—by the lofty standards he established in his MVP campaign, at least—last season.