Lee aggravated the hamstring in the third quarter of Sunday's loss to the Seattle Seahawks while splitting a sack of quarterback Russell Wilson with DeMarcus Lawrence. He left the game and did not return.
In the Week 2 win against the New York Giants, Lee was dealing with what he termed "cramping" of the hamstring in the fourth quarter, and while he could have returned, the Cowboys held him out.
Lee was limited in two practices last week, but he was credited with 11 tackles, a tackle for loss and a quarterback hurry against Seattle.
After the 24-13 loss, Lee said, "I'll get an eval from the docs (Monday) and see where we're at. Hopefully it will be a quick turnaround."
Lee missed five games last season with hamstring issues. He was limited in his work during the organized team activities, minicamp and training camp with the idea of keeping him fresh for the regular season. He has missed 10 games in his career due to hamstring injuries.
With Lee out, rookie first-round pick Leighton Vander Esch will see a larger role. He was credited with 11 tackles and a tackle for loss against the Seahawks.