Cowboys quarterback Jon Kitna has missed a second straight day of practice, making it less likely he will play the season finale.
Stephen McGee ran the first team offense Thursday and would make his first career start Sunday at Philadelphia if Kitna isn't healthy.
Kitna is dealing with a strained muscle in his side that makes it difficult for him to throw.
He was injured while throwing a touchdown pass in the first half of a loss to Arizona on Saturday
McGee played the second half and did well in his NFL debut. The Cowboys have only one practice left before playing the Eagles.
Interim coach Jason Garrett said Kitna was "walking around OK," but the club would wait at least another day before making a decision on his availability.