Freddie Roach Manny Pacquiao
Manny Pacquiao, shown with Freddie Roach, has won his last three fights by unanimous decision. Reuters

Floyd Mayweather is favored to beat Manny Pacquiao on May 2, but members of the underdog's camp are expressing supreme confidence in the boxer’s chances of winning. Mayweather is undefeated through 47 career fights, but PacMan’s trainer believes the undefeated boxer is more likely than ever to lose.

“His legs are shot,” Freddie Roach said of Mayweather, via “He can’t move anymore. That’s why he goes against the ropes, to get a breather. He says he’s trying to make the fights more exciting for the fans, but all of that is bull----. He’s never cared about the fans. He can’t move those legs.”

On paper, Mayweather’s most recent fights would back up Roach’s assessment. In his first 44 bouts, only one judge didn’t score a fight in Mayweather’s favor. But two of Mayweather’s last three victories have been via majority decision.

After his majority decision win over Marcos Maidana in May, Mayweather said that the bout was closer than it should have been because he wanted to make sure it was an exciting fight. Because Mayweather is considered a top defensive specialist, some fans and boxers alike have labeled his style boring.

While Mayweather might not seem like the same dominant fighter on his recent scorecards, he’s still looked like the best boxer in the world. His majority decision victory over Canelo Alvarez in September 2013 was one of the most one-sided wins he’s had in the last decade, and the judge who scored the bout a draw stepped down soon after, because of all the controversy. It’s unclear whether or not Mayweather truly tried to make his first fight with Maidana "exciting," but he didn’t have any problem with the challenger in their rematch just four months later.

Mayweather is nearing the end of his career at 38 years old, and Pacquiao is getting up in age as well, just two years younger than his opponent. Pacquiao isn’t considered to be nearly as good as he was five years ago, considering he was made the early favorite when it appeared that the fight would be made in 2009. But Roach believes Mayweather is susceptible to being defeated, and he’s confident that Pacquiao is the one who can end his winning streak.

“Time catches up with all of us,” Roach told Sports Illustrated. “Manny is not as consistent maybe as he used to be, but his work ethic is still there and he still trains really hard. I don’t know that it’s as easy as it used to be for him. But his legs are still good. He hasn’t lost his step at all.”

After suffering two losses in 2012, including a highly controversial defeat to Timothy Bradley, there were concerns that Pacquiao might lose his spot as one of the top two athletes in the sport. But the Filipino icon bounced back with three consecutive unanimous decisions, including an utterly dominant win over Chris Algieri in his last fight.

According to Roach, Pacquiao is as motivated as ever because he truly doesn’t like Mayweather. Roach cited Pacquiao’s stance against domestic violence, and Mayweather has done a stint in jail for a misdemeanor domestic battery charge.

It’s hard to imagine that Mayweather will lack any motivation. It's no secret that the Michigan native is intent upon retiring with a perfect record, and losing to Pacquiao would weaken his claim that he’s the best boxer of all time.

With so much on the line, Mayweather vs. Pacquiao has become must-see TV. It’s certain to shatter both pay-per-view and live gate records for any boxing event in history.