Report: NFL to consider Newton's knee injury in concussion protocol investigation

NEW ORLEANS, LA - JANUARY 07: Cam Newton #1 of the Carolina Panthers was forced to leave the game after his collision with David Onyemata #93 of the New Orleans Saints during the second half of the NFC Wild Card playoff game at the Mercedes-Benz Superdome on January 7, 2018 in New Orleans, Louisiana.
Layne Murdoch / Getty Images Sport / Getty

The NFL continues to investigate whether the Carolina Panthers followed proper concussion protocol after quarterback Cam Newton sustained an injury in last week's wild-card game. But a new dynamic has emerged.

Team officials have informed the league that a knee injury was partly to blame for Newton staggering to his feet and then stumbling to the ground after taking a blow to the head from New Orleans Saints defensive lineman David Onyemata, a league source informed ESPN's Adam Schefter. Newton - who argued he suffered only an eye injury, not a concussion, on the play - was evaluated in the medical tent on the sidelines and was cleared of a concussion by the team moments later.

The NFL has interviewed Panthers officials over the phone since the incident. The league is investigating whether the team should have taken Newton to the locker room for further evaluations, as new concussion protocols stipulate.

Newton underwent an MRI on his knee on Monday, which came back negative.