IRVING, Texas -- Zack Martin did not practice all week because of a sprained right ankle but the Dallas Cowboys' rookie right guard is encouraged he will be able to play Sunday against the Indianapolis Colts.

Martin was able to do some on-field rehab on Friday for the first time and said the ankle felt good. He is listed as questionable on the injury report.

Martin suffered the injury in last week’s win against the Philadelphia Eagles. While he was able to finish the game with a hefty tape job over his cleat, he was limping badly after the game. That he was able to continue gave him hope he would be able to play against the Colts.

Now he needs to show he can play without practice, though that is something he did while at Notre Dame.

“I just tried to take as many mental reps this week and get ready that way and stay in the film,” Martin said.

The news on right tackle Doug Free is not as hopeful, but there's a remote chance he is active as the backup tackle on Sunday. If he can’t dress for the game, then Jermey Parnell would start. Free did not practice this week because of an ankle injury.