Mayweather beat Pacquiao via a unanimous points decision last Saturday at the MGM Grand in Las Vegas in a bout that was billed as 'The Fight of the Century'.
However, after the fight, Pacquiao revealed that his performance in the ring had been hampered by a right shoulder injury, which he underwent surgery for in Los Angeles on Wednesday. According to Dr. Neal ElAttrache, who performed the surgery, Pacquiao had suffered a "significant tear" to his rotator cuff.
Pacquiao will be out of action for nine months to a year, and Mayweather has been left infuriated that the 36-year-old blamed his injury for his defeat instead of giving Mayweather credit for his performance.
"Did I text Stephen A. Smith and say I will fight him again? Yeah, but I change my mind," Mayweather told Showtime's Jim Gray. "At this particular time, no, because he's a sore loser and he's a coward.
"If you lost, accept the loss and say, 'Mayweather, you were the better fighter'.
"I'm not going to buy into the bull—- … and I don't want the public to buy into the bull—-. He lost. He knows he lost. I lost a lot of respect for him after all of this."
Mayweather also pointed out that he didn't detect any problems with Pacquiao's shoulder during their blockbuster fight.
"Absolutely not," Mayweather said. "He was fast. His left hand was fast. His right hand was fast and he was throwing them both fast and strong. Excuses, excuses."