Floyd Mayweather has earned the right to retire and deserves more respect, says Andre Berto.
Berto, who lost in his welterweight title challenge to Mayweather in Las Vegas on Saturday night, later hit out at those who had questioned the unbeaten champion.
Berto said Mayweather deserved a break. "He has done tremendous things for the sport and broken all the records and made loads of money.
"I am not here to say if a man should retire or keep going. This is a brutal sport and he put in a lot of work. Too many people are questioning that.
"You put in twenty years … running and training and being able to stay undefeated … he should be able to do what he wants."
Berto was magnanimous in his defeat on points to Mayweather, who reiterated afterwards that his 49th victory was his final fight.
Berto, a former two-time champion who has now lost four of his past seven fights, said the fight at the MGM Grand in Las Vegas was "a lot closer" than the scorecards suggested.
The judges had it 118-110, 117-111 and 120-108, all to Mayweather.
Berto paid tribute to Mayweather after a sometimes prickly fight that included the referee telling the two to stop trash-talking one another.
"He is sharp. To be 38 and still have that speed is unheard of and I commend him for that," said Berto.
"To have that 19-year run being world champion and move to greatness ... I have to commend him as a fighter because not too many people can do this; make that long walk to that ring, fight someone they do not know."
Berto, a rank outsider who made $4 million from the fight, said Mayweather's experience and ability to slip the big shots had made him a formidable opponent.
"A few occasions I got an opportunity to land a few jabs or hooks, but he's really slippery and experience played a big part. He knows how to use movement for rest time and come back with a few punches; he is real smart.
"I got a little caught up like everyone else gets caught up trying to knock him out."
Berto said: "He's smart, really smart. He knows how to con his way in certain situations to keep his distance or to use that moment to get some rest time or to use clinches to breathe and come back with a few punches.
"I used a lot of speed but he was really crafty. He was using little things to kind of get me out of my rhythm. We pushed him to the limit but we fell short.
