Training Pacquiao to take on Mayweather his biggest challenge, says Roach

MACAU (AFP) - Hall of Fame trainer Freddie Roach, who turned 55 on Thursday, has seen it all during a legendary career as a cornerman to the world's greatest fighters.

But he said on Thursday that training Manny Pacquiao to face the unbeaten Floyd Mayweather in boxing's most lucrative fight yet will be "the biggest challenge of my life".

"Floyd's undefeated. Here's a guy I first saw when he was five years old in the gym. And he was a good fighter then," Roach said.

The unbeaten welterweight Mayweather (47-0, 26 KOs) faces eight-division champion Pacquiao (57-5-2, 38 KOs) in Las Vegas on May 2.

"He's trained himself his whole life. He's a natural fighter and he makes the moves himself, I mean Floyd is a self-made fighter. He was born into this sport. He just grew with it."

Roach said Pacquiao could win but cautioned it would take a near-perfect performance and supreme concentration.

"The strategy to win the fight is very complicated and very precise," said Roach.

"Manny has to make the right moves at the right time to win the fight and this time there is no room for error.

"Mayweather is very good at moving and when he gets you to follow him, he will walk you into shots, score points and win rounds.

"But he does make mistakes here and there. Not a lot, but a couple and that's something a southpaw like Manny can take advantage of."