Cowboys LB Sean Lee out for game vs. Saints with hamstring injury

Sean Lee's hamstring injury is a big blow to the Cowboys. (Wesley Hitt/Getty Images)

Dallas Cowboys linebacker Sean Lee left Sunday night's game against the New Orleans Saints with a left hamstring injury and is not likely to return.

Lee's injury is a big blow for the Cowboys, who lose perhaps their best defensive player while trying to stop the NFL's seventh-ranked offense on its home turf.

Lee injured himself on a seemingly routine play in the first half when he came up limping after tackling Saints' running back Pierre Thomas. Lee fell to the ground before he could get off the field and walk to the Cowboys' sideline, and he looked like he could barely put pressure on his left leg.

Heading into Week 10, Lee was tied for the NFL lead in total tackles (90). The Saints scored three touchdowns in the second quarter after Lee's exit, heading into the locker room at halftime with a 28-10 lead.