Saints cornerback Marshon Lattimore collided with teammate A.J. Klein in the first quarter as the two tackled Washington receiver Maurice Harris.
Lattimore was limping as he was escorted to the locker room, but he was being evaluated for a concussion, according to the Saints.
Lattimore had the one tackle before leaving.
The 2017 defensive rookie of the year is a big part of the team’s defense, so if he can’t return, his absence would be significant.
Klein needed medical attention later in the drive.