TMZ Sports talked to The Eagle days before his AKA gym mate headlines UFC 241 on Saturday.

It'll come as no surprise Khabib thinks Cormier will win ... what might shock you, KN says this should be Daniel's last trip to the Octagon.

"Honestly I want him retire, honestly. He have job, he have money. He's like one of the greatest athlete who ever compete in the UFC."

"I really want him to retire. Because 40 years is not like 30 years. I really want him to win this fight and say, 'Hey, I enjoy with you guys long time. Right now, I have to stop this.'"

Just to be clear, these guys are tight (as you could see when DC came into the TMZ office). It's not that Khabib thinks DC's lost a step ... he believes Cormier's been so successful outside of fighting, he doesn't have to risk his body anymore.

Question is, will DC actually hang up the gloves?

Khabib doesn't think so.

"I think, no. Know why? He's like Olympic athlete level. These people cannot say 'I'm finished.'"

Nurmagomedov continued ... "I don't think he's gonna retire after this fight. Me, Coach Jav, all team, we really want him retire, cause we love him."

If DC doesn't listen ... and he fights again, there's a good chance the opponent would be Jon Jones.