TOKYO » Manny Pacquiao says his next fight will be in April or May next year as that best fits his schedule as a senator for the Philippines. And he would like a rematch with Floyd Mayweather Jr.

Pacquiao, who defeated Jessie Vargas for a welterweight title earlier this month, told reporters Friday that the opponent for his next fight is still undecided.

But he is confident he will beat Mayweather, if there is a next time. His right shoulder, which had been injured for the fight last May, is now in “100 percent” condition.

“It will help a lot,” he said in Tokyo, where he launched a boxing gym named after him, plastered with a giant photo of him on its outside wall.

Pacquiao, appearing dapper in a gray suit, flanked by two Japanese champions, Naoya Inoue and Akira Yaegashi, promised to visit often to advise younger boxers, and demonstrated with Inoue how best to punch so the other fighter can’t duck.

He said he has not spoken to Mayweather since the Vargas fight, Pacquiao’s 22nd title bout.

Officially, Mayweather is retired, but speculation is rife about his coming out of retirement. The Mayweather-Pacquiao match was the richest in boxing history. Pacquiao reportedly earned $100 million.

Pacquiao, 37, who started as a boxer at 16, acknowledged it wasn’t easy staying champ in eight divisions, and he has to “keep on eating and training hard.”

He recommended consuming a lot of well-done beef, skipping rope and doing 30 rounds a day to stay in shape.

“Don’t let laziness come to your mind,” said the boxer, who is 59-6-2.

When asked why he had returned to boxing after just several months in retirement, he said: “I felt lonely inside.”

“I can still fight. My body is still OK. And I’m here,” said Pacquiao.

“When boxing is your passion, every time you are walking up to the ring, you are always excited.”