Dallas Cowboys right tackle Marc Colombo left practice on Sunday, and is expected to miss two-to-four weeks after undergoing arthroscopic surgery on his right knee.

Colombo was limited to nine regular season games in 2009 after suffering a fractured left fibula and a high ankle sprain. Doug Free replaced Colombo last season, but is now the Cowboys' starting left tackle.

If Colombo misses the start of the regular season, veteran Alex Barron, a former first-round pick of the St. Louis Rams who was acquired this off-season, and sixth-round pick Sam Young are options to start at right tackle.