Conor McGregor's proposed mega-bout with Floyd Mayweather Jr "will never happen", according to UFC featherweight champion Jose Aldo.
Over the past few months McGregor - the first man to claim simultaneous world titles in two divisions in UFC - and boxing superstar Mayweather, who boasts a perfect 49-0 record, have become involved in almost incessant verbal sparring about the possibility of a fight.
Earlier this week, McGregor promised he would "knock Mayweather's head clean off" after the American suggested the Irishman "take care of his business" and clear the bout with the UFC.
Aldo, who was knocked out by McGregor inside 13 seconds in December 2015, believes the contest will never come to pass.
"It will never happen," he told Omnisport.
"This will only happen if the UFC wants it to. It could be against Mayweather or anyone else, if a fighter has a contract with the UFC, nobody can go over the UFC.
"I think for me, to come and fight a boxing match against a guy who always fought boxing is impossible. I have some fight principles.
"I have a respect for Mayweather, he was always a champion, I will not sell myself because I'm not a b**** to sell me for money. I am an athlete and I think of winning and being a world champion, but first I have to make a career and then, maybe I can try to fight against a champion."
Aldo rejected any notion of a rematch between himself and McGregor, whose reputation the Brazilian feels has taken a battering.
"There is no way to meet someone who does not want to fight," Aldo said. "There have been some proposals for us to fight again, the UFC has already tried to get us to do the rematch, but he never wanted to.
"My life does not revolve around him and I do not even think about what he does or what he does not, for me it does not matter. In fact, I only talk about him when someone asks me, but for me I'm just focused on myself and my goals, which is to fight and be champion.
"McGregor's reputation is already bruised. The only ones who like him are the Irish people, no-one else.
"If you ask in Brazil or in any other country, nobody cheers for him, no one considers him a champion, they always consider him a piece of s***."