Cowboys starting safety Gerald Sensabaugh and rookie linebacker Sean Lee both left Sunday's game at Washington because of concussions.
Lee left after sustaining a concussion while covering a punt return. Mike Sellers and Lorenzo Alexander doubled coverage on Lee and took him off his feet.
Lee remained down on the field at the end of the play early in the second quarter. After being tended to by trainers, Lee got up and gingerly walked to the sideline.
It wasn't immediately clear when or how Sensabaugh sustained his concussion. Team doctors were checking him on the sideline while the Cowboys offense drove 91 yards for a touchdown in the second quarter. Sensabaugh wasn't on the field when the Redskins got the ball back.
The Cowboys said neither player would return to the game.