Dallas Cowboys left tackle Tyron Smith suffered a torn left hamstring in Wednesday's practice that could sideline him for multiple months, according to sources.

Smith was hurt on a running play and went to the ground as he went to make a block on Leighton Vander Esch.

The initial tests indicated the ACL in his left knee was intact.

The Cowboys 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.