Last year, the unbeaten boxing legend silenced his outspoken rival with a 10th-round stoppage in a boxing match in Las Vegas.
"I guess his ego doesn't let him say, 'I just want to fight Conor.' Just say it".
Mayweather posted a video earlier this week which showed the former world champion walking into an empty MMA cage and then followed it up with a message to McGregor which stated: "Come at the king, you best not miss".
However, while "Notorious" is as known as much for his trash-talking as his ability to strike and grapple, he was keeping a lid on the insults, saying Mayweather would earn respect by making the crossover. "What are the odds?"
Just to be clear, Paddy Power have Mayweather as around seven-and-a-half to one to beat McGregor in his MMA debut at 41-years-old. If you've grown tired of images of cars, watches and private jets clouding up your timeline, maybe they will soon be replaced (or at the very least, supplemented) with training photos from an actual fight camp.
Their fight is to be for McGregor's title but the Dubliner has yet to be officially stripped of his belt, further muddying the waters of the 155-pound division as negotiations continue.
"If it is (all talk), it will follow him for the rest of his days that he did not do it", McGregor said.
"There's the current interim lightweight champion [Tony Ferguson], there's an undefeated Dagestani [Khabib Nurmagomedov], maybe a big Russian event, there's obviously the [Nate] Diaz trilogy, of course the Mayweather fight is there". But if he does do it - I know he is flirting with it - I would have respect for him.
"I'm delighted for her, absolutely over the moon for her", McGregor said.
"They are who I'm thinking of, but the fight game changes so quick, so many times, so we'll see".
"He's engaging, we're engaging, so we'll see".
'I'm now in negotiations to face my next opponent and we have many options, there's the current interim lightweight champion, there's the undefeated Daegestani, that could be a big Russian event. I said I would do it [fight with boxing rules], and I stepped up and I done it. "Time's is good, life is good".
McGregor was also asked for his thoughts on fellow UFC superstar Ronda Rousey signing for the WWE, and the Irishman gave her his full support.
"I'm delighted for her, absolutely over the moon for her", McGregor added to journalist Adam Glyn, in NY.