McGregor's journey from a plumber in Dublin to one of the most well-known mixed martial arts (MMA) stars globally is reminiscent of a Hollywood movie. His 13-second knockout of José Aldo solidified his status as an iconic figure in the sport.
Since then, McGregor's brand has grown exponentially, attracting both admirers and critics. However, one vocal detractor is former boxing world champion Paulie Malignaggi.
In 2017, Malignaggi engaged in sparring sessions with McGregor at the UFC's Las Vegas training facility, spanning over eight and then 12 rounds. The second session gained infamy due to disputed knockdowns, leading to a heated disagreement and Malignaggi storming out of the training camp.
The feud between Malignaggi and McGregor has continued, with Malignaggi now claiming that McGregor's success is attributed to luck and an effective marketing team.
"McGregor was lucky to achieve what he did in his career. Physically and talent-wise, he's up there, but just because you can do a bunch of high kicks from a Jean Claude Van Dam movie doesn't mean you're a fighter. You need guts, a willingness to succeed, and a readiness to enter the trenches. If you don't have that, you're going to fade," said Malignaggi to Action Network.
"We've talked about AJ losing that edge, but McGregor is on a different level. McGregor will quit on you; he does quit. AJ does not take as many risks anymore, but at least he's not quitting. McGregor is an outright quitter. He is a fighter that was not as good as advertised, there was great marketing behind him.
"And the money he's made now isn't helping, so you've got a problem - all he's going to do is continue to be a punching bag. If you're a punching bag in your twenties, you'll definitely be a punching bag in your thirties."
McGregor's trash-talking became one of the most well-known aspects of his brand. The "who the f**** is that guy" phrase is still famous today.
McGregor during his career backed his talk and swagger up by becoming a two-time weight champion in the sport. There could have been a time when Malignaggi and McGregor might have fought, but that never materialised. According to the 43-year-old Malignaggi, it was a wise decision by McGregor as he believes he would have ruined McGregor's aura.
"I'm a better trash talker than McGregor; that's one of the reasons he did not fight me. I would have trashed him in the press conferences and the fight.
"It would have ended all of the hysteria around him because I would have destroyed him in the trash talking and in the ring. I would have ruined the whole aura around him. He was smart not to pull the trigger on a fight with me," he added.