Dallas Cowboys quarterback Tony Romo has underdone season-ending back surgery, the team said on Friday.

Romo had a procedure to repair an injury incurred in last Sunday's game against the Washington Redskins, Dallas head coach Jason Garrett said.

Back-up quarterback Kyle Orton will start in Sunday's crucial clash with the Philadelphia Eagles.

The winner will advance to the NFL playoffs, while the loser's season will be over.

Orton has appeared in two games this season, completing three of five passes.

(Reporting by Andrew Both in Cary, North Carolina, editing by Gene Cherry)