Nurmagomedov defeated McGregor at UFC 229.
Khabib Nurmagomedov, who defeated McGregor at UFC 229 in October, reportedly commented on McGregor's retirement while speaking at a university in Moscow on Tuesday.
He said that McGregor "couldn't reach a deal with the UFC, and it's so they feel they've lost him and they could lose money," according to ESPN.
McGregor has been pushing for UFC ownership shares, however UFC president Dana White shot down the possibility during an interview with KLAS-TV on Sunday.
"... he's stuck on this thing where he wants a piece of the ownership," White said, "and that's just – if you look at basketball, Michael Jordan didn't own a piece of the league, and the list goes on and on. Is Conor very valuable to the sport and to the brand, the UFC? Of course he is. That's a tough one, but I think there's other ways that we can make him happy."
White also said that he doesn't believe McGregor is truly retired, a sentiment further echoed by Nurmagomedov on Tuesday.
"I don't think he's finished," Nurmagomedov said.