With just under five minutes left, Kuechly went in for a tackle on Saints running back Tim Hightower but wasn't able to get up after making the hit.
After being taken to the Panthers' locker room in cart, the team announced that Kuechly was being evaluated for a concussion.
Kuechly was in tears as he was being carted off the field, which could mean that he knows he might miss some time due to the injury.
The Panthers linebacker has a history with concussions and missed some major time last year after suffering a concussion in Week 1.
After that opening week injury in 2015, Kuechly was in concussion protocol for 34 days before returning to action. He missed three games, and it might have been a fourth if not for an early bye week for the Panthers.
Any of those three players missing a lot time going forward would be a big loss for Carolina.
Panthers coach Ron Rivera didn't have an update on Kuechly after the game.
"I'm not going to speculate until I talk to the doctors," Rivera said.
The good news for the Panthers is that they'll have 10 days off before playing their next game Nov. 27 in Oakland.