The NFL and the NFL Players Association are opening an investigation into whether the Carolina Panthers properly followed the league’s concussion protocol for quarterback Cam Newton on Sunday.

In the fourth quarter of the Panthers’ wild-card matchup against the New Orleans Saints, Newton thought he’d eluded Tyeler Davison, and as he tried to stand upright he collided with defensive tackle David Onyemata.

Newton was clearly shaken up, and as he walked toward the Panthers’ sideline, he fell to his knees. He was met by the team’s trainers, went into the blue medical tent and was back on the bench.

He missed one play.

Newton said after the game the problem was with his eye, not a head injury.

On Monday, Carolina players, coaches and interim general manager Marty Hurney met with reporters to wrap up the season. Hurney said, “We did everything right,” when asked about Newton’s treatment.

Asked if Newton had displayed any signs of a brain injury, coach Ron Rivera said, “I don’t think so. But again, I’m not the doctor. I know he still has to do his exit physicals. So they’ll get a chance to look at him.”

This is the second time this season the Panthers are being investigated for their handling of Newton as it pertains to the concussion protocol.

Newton took a helmet-to-helmet hit in the regular-season opener, against Denver, and did not leave the field. The Panthers were cleared in that situation.

Last month, the Seattle Seahawks were fined $100,000 after an NFL-NFLPA investigation found they hadn’t followed the rule with quarterback Russell Wilson.

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