Benwikere had started four straight games with every-down left corner Charles Tillman nursing a knee injury. Before that, Benwikere was the starting nickelback.
Tillman, who practiced on a limited basis this past week, said he "thinks" he could play next Sunday against the New York Giants if needed.
"We'll see what happens," Tillman said.
It wasn't all bad news for the Panthers (13-0) on the injury front. Tight end Greg Olsen, who grabbed his knee on an incompletion in the end zone late in the first half, said he is fine and should be ready to face the Giants.
Olsen, who leads Carolina in receptions, said he could have played in the second half if needed.
Running back Jonathan Stewart, the Panthers' leading rusher, did not play in the second half because of a foot injury, but coach Ron Rivera said Stewart was all right, as well.
The loss of Benwikere was the Panthers' most immediate concern because of his ability to play two positions.
"He's such a key asset to us on this defense," safety Kurt Coleman said.
Finnegan was lured out of semi-retirement two weeks ago to primarily play the nickel spot, but he has been a productive every-down corner over the course of his career.
Rivera said the Panthers also will look at a couple of players from the practice squad to fill Benwikere's roster spot. Undrafted rookie corner Lou Young is the only corner on the practice squad.