Freddie Roach believes that his prized fighter Manny Pacquiao will score a knockout win over Floyd Mayweather Jr. in their upcoming fight on May 2 at MGM Grand Arena in Las Vegas, Nevada.

Roach said in an appearance in The Jim Rome Show that he has always been convinced that Pacquiao has the tools to stop Mayweather even before rumors about the mega-buck fight first surfaced in 2009.

Six years later and with both fighters past their respective primes, Roach is still a firm believer that Pacquiao has the power to knock Mayweather out and hand the reigning pound-for-pound king the first loss of his boxing career.

Mayweather, who boasts a perfect 47-0 record with 26 knockout victories, is considered by many as the favorite to win in the upcoming bout, which is expected to become the richest fight in boxing history.

The Hall of Fame trainer said that he can see Pacquiao is very motivated to prove something based on the way the Filipino boxing icon has been training for the biggest fight of his career.

"We do have a good game-plan going down, I do think he will knock this guy out," Roach said via BoxingScene. "Because again, he's really motivated and again, I don't think he likes this guy and this is the first time in my life I've really come across that."

Pacquiao, who has a 57-5-2 fight record with 38 knockout victories in his career, has not scored a knockout victory since stopping Puerto Rican Miguel Cotto during their World Boxing Organization welterweight title fight in 2009.

Roach admitted that religion changed Pacquiao's approach inside the ring, confirming that the reigning WBO welterweight champion, who will also try to steal the World Boxing Council and World Boxing Association welterweight titles from Mayweather, did not show killer instinct in his recent fights.

But against Mayweather, the veteran boxing trainer is convinced fight fans will see a different Manny Pacquiao in the highly anticipated Cinco de Mayo weekend super showdown.

"The thing is the religion has taken away the killer instinct a bit over the years and I will agree with that somewhat," Roach said. "For some reason, Manny Pacquiao, I've never seen him dislike an opponent in my life, but you know what, he doesn't like this guy. He won't say anything bad about him, but he won't say anything good about him."

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