The Cowboys are without starting safety Malik Hooker, who fractured his forearm in the season opener. P.J. Locke started for him, but lasted only three plays.
He was injured with 8:48 remaining in the first half on a non-contact play.
Locke was running toward Rachaad White, who caught a short pass from Jayden Daniels, when he suddenly pulled up.
Locke needed help getting off the field but walked slowly to the X-ray room after an examination in the sideline medical tent.
He is questionable to return with a foot injury.
Markquese Bell has replaced Locke in the lineup.
The Cowboys lead 10-0, and CeeDee Lamb has five catches for 89 yards and a touchdown. He was wide open in the end zone for a 3-yard score. Dak Prescott is 8-of-11 for 101 yards and a touchdown.
The Cowboys settled for Brandon AubreyâÂÂs chip-shot, 25-yard field goal on their second drive after stalling at the Washington 6.