Thornton (ankle) has been ruled out for the rest of Monday's game against the 49ers, Darin Gantt of the Panthers' official site reports.
Thornton has mostly served on special teams this season, but he started the second half at outside corner after Jaycee Horn (concussion) was ruled out. Thornton suffered an ankle injury in the third quarter, which is severe enough for him to not return to Monday's game. With both Horn and Thornton done for the day, Akayleb Evans is the next man up at outside corner opposite Mike Jackson.