Center Phil Costa, who returned from a back injury last week to help the Cowboys rush for 227 yards, was limited in practice Wednesday because of a knee injury.
The third-year center drew raves from coach Jason Garrett and the player-grading site Pro Football Focus for his play last week against Baltimore.
But his backup, Ryan Cook, did not practice Wednesday because of a hamstring injury, leaving only guards David Arkin and Mackenzy Bernadeau as possible center options.
Running back DeMarco Murray (foot), defensive end Sean Lissemore (ankle) and punter Chris Jones (knee) also were held out of practice. Murray is not expected to play Sunday against Carolina, but he seemed in good spirits Wednesday at Valley Ranch. He sat in his socks and smiled as he autographed footballs, but he did not speak with reporters.
Linebacker Anthony Spencer (shoulder) and punter Brian Moorman (groin) were limited in practice.
Cornerback Morris Claiborne (knee) had a full practice.
Cornerback Mike Jenkins (shoulder) did not appear on the practice report.
-- Carlos Mendez