Chargers receiver Keenan Allen exited early in the first half of Monday's night game against the Saints not long after registering the first points of the contest and was unable to return.
The team announced at the start of the second half that the veteran wideout would not return to the game because of a back injury. He was initially listed as questionable.
"Keenan went out with lower back spasms and that's the last I've heard," Chargers coach Anthony Lynn explained after the game. "I know he couldn't go and believe me, he came back in, he tried but he just couldn't go."
The Chargers would go on to lose 30-27 in overtime.
NFL Network's James Palmer reported shortly after Allen's exit that the receiver was sitting alone on the bench with no trainers or anyone tending to him. He later added that Allen continued to stretch out on his own on the Chargers sideline before a trainer came over to assist him.
Prior to exiting, Allen caught both of his targets for 29 yards, including a superb 17-yard reception in the end zone to give L.A. an early lead.