Dallas Cowboys' Tyron Smith facing surgery for torn hamstring, possible December return, sources say

FRISCO, Texas — Dallas Cowboys left tackle Tyron Smith is unlikely to return before December after his left hamstring tore and came off the bone during Wednesday's practice, sources told ESPN on Thursday.

Smith could have surgery as soon as Thursday, pending a potential second opinion, sources told ESPN.

He was hurt on a running play and went to the ground as he went to make a block on linebacker Leighton Vander Esch. He was able to walk to the locker room without any help, and the initial tests indicated the ACL in his left knee was intact.

Tyron Smith has missed 20 games in the last two seasons for the Cowboys, and the impact he has on the offensive line has been massive:

Smith was spotted leaving the locker room after practice and did not appear to be limping.

The loss of Smith, an eight-time Pro Bowler and protector of Dak Prescott's blind side, creates a gaping hole on an offensive line that was already dealing with questions before the Sept. 11 opener against the Tampa Bay Buccaneers.

Dallas drafted Tyler Smith in the first round to be the left tackle of the future and has used him exclusively at left guard during training camp and the first two preseason games. Smith is also dealing with an ankle injury that kept him out of the past two practices.

The Cowboys have played Josh Ball, who was selected in the fourth round last year but did not play as a rookie because of an ankle injury, at left tackle with the first team when Smith has taken breaks. They also drafted Matt Waletzko in the fifth round this year, but he only returned to practice this week after dealing with a shoulder injury for most of training camp.

Coach Mike McCarthy has singled out Aviante Collins' play during camp, but Collins has not played in a