Freddie Roach didn’t really want to spend his 55th birthday on Thursday halfway around the globe to be in the corner of his pupil, Zou Shiming.

Not because the seven-time Boxing Writers trainer of the year didn’t want to be with his two-time Olympic gold medalist from China, who is fighting in Macau for the IBF flyweight title on Saturday against champion Amnet Ruenroeng (HBO2, 5 p.m. ET) in just his sixth professional fight.

Roach simply didn’t want to leave his most prized pupil, Manny Pacquiao, to train on his own back in Los Angeles.

Yet it was Pacquiao, who last month signed to fight Floyd Mayweather Jr. on May 2 at the MGM Grand in Las Vegas in what is expected to be the most lucrative and most publicized fight of all time, who insisted Roach go.

“I thought I should be in Los Angeles with Manny Pacquiao,” Roach told USA TODAY Sports by phone from Macau this week. “But Manny told me, ‘Freddie, I’m going to be all right now.’ He said, ‘You go and be with Shiming and help him win a world title.’ I said no, I’m going to stay here with you. He said, ‘No, I can take care of myself for five days. You being with Shiming will help him win a world title’, and I know (Pacquiao) wants Shiming to win badly.”

Pacquiao will spend the time between now and May 2 training in Los Angeles at Roach’s Wild Card Gym, unlike past fights where he’s spent most of his time training in the Philippines. Roach said Pacquiao told him that “the distractions and the (people and media) trying to get at him in the Philippines was just too much. He told me he had to get out of there.”

While Pacquiao, 36, and Mayweather, 38, a notorious trash-talker, have both been saying little since the fight was signed, it’s not been the case with Roach, who has been as outspoken as ever.

He told Filipino TV network ABS-CBN last week that he believed Mayweather’s manager, Al Haymon, was offering potential Pacquiao sparring partners money to not spar with the Filipino star.

“I’m hiring sparring partners, Al Haymon’s people calls them up and offers more money for them not to come,” Roach said. “(But) I’m not worried about those guys. We have four very good sparring partners for Manny that are Mayweather look-alikes.”

He also told Yahoo Sports that he thought Mayweather’s current trainer, Floyd Mayweather Sr., the fighter’s father, was not near as good as Mayweather’s former trainer, his uncle Roger Mayweather, and that it would cost Mayweather on fight night.

“I think Floyd Sr. is a terrible cornerman, I really do,” Roach said. “That’s going to work to our advantage on fight night because in the corner, I’m not going to be nervous and I’ll be able to calmly talk to Manny and make whatever adjustments we have to make.

“But Floyd Sr. can’t get his message out in that minute (rest) period. He gets so excited and worked up and he starts to stutter so he can’t give his fighter any useful (information).”

Roach has said training Pacquiao to beat Mayweather is the biggest challenge of his life. He told USA TODAY Sports that while the pressure is building, “I’ve been feeling the pressure for the last five years. It’s the most important fight for us because for the past five years it has been the only fight the fans have wanted.

“So yes, we do feel more pressure than usual. But I think the real pressure is on Floyd. That “0” means more to him than anything, It’s his identity. And the further along he goes with each fight, the heavier the pressure is on him. It’s not unlike pitching a no-hitter. It’s a breeze the first few innings, but in the late innings? You have to really bear down and you aren’t as fresh and comfortable as you were earlier. Things creep into your mind.

“The key for us is to take Floyd out of his comfort zone. He hates that. We have already done that by making him fight Manny. He never wanted that fight. Manny and the fans forced him to take the fight. He ran out of road. His excuses no longer held water. The next step is to take the fight to him on May 2. Manny winning that first round is critical. And Manny winning that fight will be a public service for boxing.”

With the 60-40 split of the purse the fighters signed in the contract for the fight, where Mayweather is getting 60%, the world’s top pound-for-pound fighter is expected to make as much as $120 million, while Pacquiao, generally considered No. 2 or No. 3 P4P, could make as much as $80 million, which would be easily the biggest career purse for each.

Roach is well aware of the magnitude of the May 2 fight, and said, in his opinion, the whole world wants Pacquiao to win this fight. Why? “Because he’s a good role model, a good guy,” Roach said. “Mayweather is a good athlete and should be a good role model, but he’s not.”

Roach said there is no rematch clause in the contract for either Mayweather or Pacquiao. Asked if Pacquiao might retire after this fight, win or lose, Roach didn’t think so.

“I don’t think so because he’s so good at boxing” and still loves to do it, the trainer said. “I think he wants to (eventually) become the president of his country, and I think he’ll be old enough in a couple of years.”

Running for president of the Philippines would be a huge step for the two-term congressman.

But, says Roach, “this one is bigger now.”