Floyd Mayweather described Manny Pacquiao as a "sore loser" and "coward," and said he has no interest in a rematch.
In an interview set to air on Showtime this weekend, the middleweight champ ripped Pacquiao for blaming his loss at Saturday's title fight on a shoulder injury -- one he failed to disclose beforehand.
"Excuses, excuses, excuses," Mayweather told sportscaster Jim Gray in excerpts released in advance and cited by The Associated Press.
"I'm not going to buy into the bullshit, and I don't want the public to buy into the bullshit," Mayweather said, according to CBS Sports. "He lost. He knows he lost. I lost a lot of respect for him after all of this."
Mayweather also said he could "absolutely not" detect any sign of Pacquiao's injury.
"He was fast," Mayweather said in quotes Showtime released on Twitter. "His left hand was fast. His right hand was fast and he was throwing them both fast and strong."
Pacquiao is facing possible disciplinary action for failing to disclose the injury, which led to a surgery that could keep him out of the ring for up to a year.
Mayweather's remarks stand in sharp contrast to the generous praise he heaped on his rival after their long-awaited showdown in Las Vegas.
“Manny Pacquiao is still a champion,” Mayweather said during an in-ring interview. “He still has a lot left. I was the better man tonight -- more calculated fighter, took my time, had patience.”
Mayweather also told ESPN's Stephen A. Smith via text message that he'd be up for a rematch.
However, Mayweather told Gray that he had since changed his mind.
"At this particular time, no, because he's a sore loser and he's a coward," Mayweather said. "If you lost, accept the loss and say, 'Mayweather, you were the better fighter.'"
The interview airs at 9 p.m. on Saturday night on Showtime.