Los Angeles Rams quarterback Matthew Stafford left to be evaluated for a concussion in the third quarter against the Saints and did not return.
Stafford had connected on 11 of 18 passes for 159 yards and two touchdowns at the time of his exit.
Backup quarterback Bryce Perkins entered the game with the Rams trailing, 24-14. He had five rushes for 39 yards and also completed five of 10 passes for 64 yards.
The Rams would go on to drop a fourth straight game, 27-20.
The need to evaluate Stafford for a concussion came after the QB missed L.A.'s Week 10 game against the Cardinals due to being in concussion protocol. Stafford cleared the protocol on Friday after being a full participant in practice all week.
"Obviously, we need to make a smart decision for Matthew and see where we're at with that," coach Sean McVay said after the loss. "I know how he was feeling and communicated that and then we made the decision that it was not gonna be in his best interest to have him continue to play. ...
"As far as it relates to Matthew, we're going to be smart for him. He's such a warrior, he's such a stud competitor. I know how bad he wants to be out there and thought he played really well with the opportunities that he did have."
The Rams travel to Kansas City to take on the Chiefs next Sunday.
