LAS VEGAS – Mario Barrios admits he isn't sure what to expect from Manny Pacquiao on Saturday night.

The Filipino legend's handlers have all said he has displayed speed and power throughout this recently completed training camp comparable to when Pacquiao was at his physical peak.

Of course, if the eight-division champion more resembled the 46-year-old man he is in preparation to battle Barrios, Pacquiao's people obviously aren’t going to admit it publicly before their 12-round fight for Barrios' WBC welterweight title at MGM Grand Garden Arena.

The ever-polite Pacquiao (62-8-2, 39 KOs) acknowledged during a press conference Wednesday at MGM Grand that he rested more during his first legitimate camp in nearly four years. He also assured those concerned about the iconic ex-champion fighting at such an advanced age that they have nothing to worry about.

Barrios (29-2-1, 18 KOs) smiled on stage as Pacquiao predicted that the San Antonio native’s style will help them provide plenty of entertainment during their 12-round pay-per-view main event (8 p.m. ET; 5 p.m. PT; $79.99). If Pacquiao is indeed up to the challenge of testing a fighter 16 years younger and 6 inches taller than him, Barrios is more than prepared to go toe-to-toe with the powerful southpaw.

"There's so much unknown," Barrios told The Ring, "so I literally have to prepare as if I'm fighting a prime Pacquiao and we’re gonna be going to war for 12 rounds. I have to make sure I'm in the best shape possible for the fastest, quickest Pacquiao we have seen. And then I'll be able to answer those questions come fight night."

Bob Santos, Barrios' trainer, reminded Barrios throughout training camp that the favored defending champion must be ready for his returning opponent to perform the way he did the night a 40-year-old Pacquiao dropped Keith Thurman in the first round and became the first fighter to defeat Thurman.

Barrios, The Ring's No. 3-ranked welterweight, will defend his title almost six years to the day since Pacquiao beat Thurman by split decision at MGM Grand Garden Arena. Pacquiao hasn't won a fight since he edged Thurman in July 2019, but Santos learned an invaluable lesson the last time he underestimated one of the greatest fighters of the 21st century.

"What's the old saying? Fool me once, shame on you. Fool me twice, shame on me," Santos told The Ring. "I picked Keith to really put a clinic on Manny. The next thing I know, Thurman's on the deck. The next thing I know, it’s the end of the 12th round and Pacquiao's hand is being raised.

And I’m sitting there in disbelief, saying, 'He can't do this at 40.' I knew Thurman because Robert Guerrero fought Thurman and I know what kind of athlete he is, I know what kinda boxer he is, I know how good his feet are. And it was like, 'I didn't just witness this.’ And I can’t allow that to happen to us. We have to be prepared for that Manny Pacquiao."

Santos and Barrios also tried to put Pacquiao's loss to Yordenis Ugas in his most recent fight out of their minds the past couple months.

Pacquiao announced his retirement five weeks after Ugas upset him by unanimous decision in their 12-round fight for Pacquiao's WBA welterweight title in August 2021 at T-Mobile Arena. He accepted the right-handed Ugas as his opponent on less than two weeks' notice, though, because then-unbeaten southpaw Errol Spence Jr. suffered a detached retina while training and withdrew from his fight with Pacquiao.

"The Ugas fight I take as a one-off," Santos said. "You're getting ready for Spence for three months and a week before the fight it's, 'Oh, by the way, we're switching opponents from a southpaw to a right-handed, Olympic bronze medal-winning, long Cuban.' That's no easy task for anybody."