Floyd Mayweather Jr claims he did not spar in training for a month due to a hand injury before his victory over Conor McGregor.
The American struggled against the unorthodox style of UFC star McGregor, making his boxing debut, in the early stages of Saturday's bout at Las Vegas' T-Mobile Arena before taking charge of proceedings and stopping his rival in round 10.
Consequently, Mayweather extended his perfect record to 50-0, surpassing Rocky Marciano's all-time benchmark. Yet he revealed in his post-match news conference that an injury had forced him to alter his preparations.
"We had a cool training camp, but I didn't do any sparring for the last month," he said.
"My hands are real brittle and I wanted them to be solid when I came out here.
"If I had a serious hard injury I wouldn't have been able to hit so hard."
Pressed on the matter, Mayweather added: "I didn't do any sparring for the last month.
"No excuses, he fought a hell of a fight. But I broke him down. He was a hell of a fighter standing up, he kind of shocked me.
"It was an injury [that led to the lack of sparring] and I wanted my hands to be 100 per cent. I wanted to able to hit him hard."
The fighters drew headlines for their trash-talking outside the ring ahead of Saturday's contest.
Mayweather said the duo's antipathy was genuine, but there is respect between the two.
"Talking doesn't win fights, fighting wins fights. Meaning that when we were on stage for the weigh-in I don't have to do no more talking," he said.
"[After the fight] I just told him 'you're a tough competitor, good fight, keep up the good work'. I'm always going to carry myself like a gentleman.
"You've got to realise in the press conference, when we were doing what we were doing, that's my job. He's 'The Notorious', I'm the 'Money Man'.
"We had arenas packed like this, we had to give them a show. A lot of people thought it was fake, no. We didn't like each other, we probably still don't, but we have to act like gentleman."
Mayweather came out of retirement to take the fight, but insists he will not return for a second time.
"You will never see me in the ring again. I wanted to break records and do different things. And tonight we broke the Mayweather-Pacquiao record for pay-per-view buys," he explained.
"I'm very comfortable, I didn't have to come back. I'm not a fool. If I see an opportunity to make $350million in 36 minutes then I'm going to do it. But that's it. I won't be back again."