Chris Gamble (shoulder) to have MRI

CHARLOTTE, N.C. -- Panthers coach Ron Rivera says starting cornerback Chris Gamble will have an MRI on his right shoulder to determine if he has a torn labrum, the same injury that sent offensive lineman Mike Pollak to injured reserve earlier this season.

Gamble has been ruled out for Sunday's game against Dallas and Rivera is "concerned" he may end up on injured reserve.

Captain Munnerlyn will start in Gamble's spot.

Rivera says Gamble, who has started 117 games in nine seasons, first injured the shoulder against Atlanta on Sept. 30. He sat out Carolina's game against Seattle the following week. He reinjured it in practice this week.

Rivera also says middle linebacker Jon Beason is "very doubtful" for Sunday and that rookie Luke Kuechly will make his second start at middle linebacker.