Top UFC lightweight Arman Tsarukyan dismissed McGregor, one the promotion's biggest attractions, saying that he was only in it for the money.
The Russian fighter, who aims to put two to three big fights under his belt this year, was asked his opinion of the Irishman in an interview with MMA.metaratings.ru, a top ringside publication.
“He's done,” Arman declared. “He's a lame duck. I think he'll have two or three more fights maximum, just for the hype sake.
“He doesn't have the aggression, the fire that he used to have. He fights for pleasure, not even for money. There's nothing wrong with his money."
Arman's next fight will take place at UFC Fight Night 202 on February 26 in Las Vegas when he takes on Joel Álvarez, the Spanish fighter.
Tsarukyan had his last fight against the American Christos Giagos in September of 2021 at the UFC Fight Night 192 tournament which he won by TKO in the first round.
McGregor, meanwhile, last appeared in the Octagon against American Dustin Poirier in July 2021 at UFC 264. Dustin won by TKO in the first round after Conor broke his leg.
This fight was the third one between McGregor and Poirier after their first encounter, which took place in September 2014, ended in favour of the Irishman by TKO.
The second one, held in January 2021, saw the American win by TKO.
Conor who has 22 wins and six losses, has recently been heavily promoting his return to fighting with fans’ expectations rising that they will see the Notorious in the Octagon this year.
McGregor has been shared photos at his old weigh ins, promising he will make championship weight.
Sharing the snaps, McGregor said in his first post: "7 years ago. Still here rocking championship weight."
McGregor shared a second post, saying: "Championship weight, it’s all we know."
However, in a recent 'best ever' fighter list compiled by Dana White, McGregor's foe, Khabib Nurmagomedov, was ranked fifth while Conor was snubbed altogether.
The UFC president picked the likes of Kamaru Usman and Jon Jones ahead of the Russian, who went undefeated during his time in the UFC's lightweight division.
The 33-year-old retired in 2020 after defeating the likes of Justin Gaethje and bitter rival McGregor - and goes down among many fans as the greatest fighter ever within the company.
But White named four better fighters than Khabib, who retired as UFC's pound-for-pound king, including Jon Jones, Kamaru Usman, Georges St-Pierre and Anderson Silva.