Even Manny Pacquiao is uncertain whether his 26-year professional boxing career will end Saturday night when he faces Yordenis Ugas for the WBA welterweight title.

Pacquiao has plans and ambitions reaching far beyond the fight game at this point in his life and that's why he might be saying goodbye at T-Mobile Arena.

If he enters the presidential race in his native Philippines a few weeks after this bout, as nearly everyone expects, he will be running for a job that would effectively prevent him from fighting again.

While the 42-year-old Pacquiao has said nothing official, his fans around the globe realise it's at least one of the final chapters in a boxing story with few equals.

"I never imagined what I would have accomplished in boxing from the beginning of my career leading up to now," Pacquiao said.

"I went from nothing to something in order to be an inspiration for people both inside and outside of the ring."

Almost nobody in the history of boxing could do what Pacquiao intends to accomplish over the next year - although that's been true for pretty much every year of the Filipino senator's time in the professional fight game.

If being an eight-division world champion was an achievable goal, plenty of boxers would have a collection like Pacquiao's closet full of belts.

Pacquiao (62-7-2, 39 KOs) is returning to the ring after a two-year absence - the longest of his career - to fight for another world title in front of a big Vegas crowd and a pay-per-view audience.

In the next few weeks, almost everyone in the Philippines expects him to declare his candidacy ahead of the May 2022 presidential election.

A presidential campaign would be longer and more gruelling than any training camp in Los Angeles, where he teamed up again with Freddie Roach to prepare for one more title challenge.

Pacquiao is a solid favourite to beat Ugas (26-4, 12 KOs), the cagey Cuban veteran who got a surprising chance for a life-changing win at late notice.

"I feel young right now," Pacquiao said. "I'm just happy with what I'm doing, because boxing is my passion. I enjoy training camp, and I was excited to sacrifice and be disciplined every day to prepare for a fight like this."

Pacquiao's power and speed hadn't diminished significantly in his last bout against Keith Thurman.

If he shows up against Ugas with the same combination of skills, it likely would be too much for the man who holds the belt Pacquiao took from Thurman in 2019 before the WBA abruptly awarded it to Ugas earlier this year.

"I didn't like that someone took my belt without challenging me in the ring," Pacquiao said.

"I'm glad that we can settle that dispute about the WBA title. It's always better to talk in the ring."