Saints quarterback Derek Carr was injured Monday night against the Chiefs

While Carr lamented that he couldn't be on the field with his teammates to finish the game, he admitted, “I couldn't do what I had to do.”

Coach Dennis Allen said he was advised by medical staff that Carr had a left side injury and would not be able to continue.

Carr struggled with multiple injuries last season, his first with the Saints, but managed to start all 17 regular-season games despite failing to finish against Green Bay and Minnesota. Against the Packers he sprained the AC joint in his right (throwing) shoulder and against the Vikings he suffered a concussion and a right shoulder injury.

“I asked if you could do something about it,” Carr said of the slash. “They said there wasn’t enough time for that.”

Carr said it was not a hit that caused the injury; rather, as he turned to make the throw.

“I just don’t know yet,” said Carr, who threw his 250th career touchdown Monday night and passed the 40,000-yard mark. “It wasn’t like it was a pain thing. If you can handle the pain, then you can leave. I just can't do what I want to do. Obviously it's fresh, it just happened, but you know me. “I'll do everything I can to make sure I'm there.”