Ricky Hatton must prepare to face a complete fighter when he steps into a Las Vegas ring on May 2 to face Manny Pacquiao, according to the Filipino's trainer Freddie Roach.

Hatton (45-1, 32 KOs) and Pacquiao (48-3-2, 36 KOs) meet at the MGM Grand Garden Arena for the Englishman's IBO and Ring Magazine light-welterweight titles with both fighters claiming to have become more refined in their fighting styles than earlier in their respective careers.

Hatton, who last year hired Floyd Mayweather Sr to temper his brawling instincts, put on an impressive performance last November with his new trainer in his corner for the first time to stop American Paulie Malignaggi in the 11th round of their contest.

Roach, meanwhile, believes Pacquiao is becoming a complete boxer, something he has tried to develop in a fighter who once relied solely on his speed and power at the expense of defence and poise.

The American trainer, Pacquiao's handler since 2001, believes his southpaw charge became a genuine boxer in his WBC lightweight title victory over David Diaz last June and continued that trend in his upset win at welterweight over Oscar De La Hoya in December.

"We've been working on that a long time and it's finally coming into play," said Roach. "He's boxing a lot smarter now.

"It started with the Diaz fight where he boxed a beautiful fight. His defence is much better, the Oscar fight was similar and the way things are going, the Hatton fight will be the same."

Roach also said he did not buy into the perception that Hatton had a size and strength advantage over Pacquiao.

"I disagree," he added. "Manny's really settled in the 140-pound weight division, he's really getting used to the weight and he's knocked out four sparring partners out of seven and in training camp he's been looking very strong.

"Ricky will be a little heavier by fight time but being heavier really doesn't make you stronger.

"I know I have the stronger fighter going into the fight, I guarantee that."

Mayweather Sr, however, believes his man is also fast improving and Roach is giving his man some futile advice.

"The name of the game is hit and don't be hit and that's what I've been getting Ricky to do and he's most definitely going to perfect that," Mayweather said.

"I heard Freddie Roach saying on TV (to Pacquiao) 'don't let him hit your body, don't let him hit your body.'

"Of course he's going to hit his body, it's just a matter of time. We've got 12 rounds in this fight and he's not going 12 rounds without his body being hit."