Manny Pacquiao hopes to defy the odds and make history when he steps into the ring again after a nearly four-year retirement against World Boxing Confederation (WBC) welterweight champion Mario Barrios on Sunday morning (Manila time) at the MGM Grand Garden Arena in Las Vegas, Nevada. 

Pacquiao, 46, aims to become the second-oldest world boxing champion after Bernard Hopkins and the first to win a boxing title post-Hall of Fame induction. 

But the Filipino boxing legend is the heavy underdog against the much younger Barrios. 

Pacquiao is a +220 underdog at BetUS, one of the top US sports betting sites, according to Gameshub.com. 

Barrios, 30, is the odds-on favorite at -280 to send Pacquiao back to retirement. 

"I'm ready to get backlash if I retire him -- it comes with it," Barrios told The Ring.

"Any fighter in my division would be more than happy to take this fight as well. It's just my job to go out there and do what I do best."

Barrios beat Pacquiao's old tormentor Yordenis Ugas to win the WBC interim welterweight title in 2023. He retained the title by a unanimous victory against Argentina's hard-punching Fabian Maidana. 

Barrios was elevated to become the full-fledged WBC welterweight champion last year after the WBC demoted Terence Crawford. 

The Mexican-American vows to avenge the losses of his countrymen against Pacquiao, who was called the "Mexecutioner" for beating Mexico's best fighters in his generation, which include Marco Antonio Barrera, Juan Manuel Marquez, Erik Morales, Antonio Margarito and Oscar De La Hoya.

"He's beaten a lot of Mexican fighters before, but he hasn't faced a Mexican fighter like me," Barrios said. 

“Every time I step in the ring, I represent my Mexican roots and indigenous roots very proudly."

Barrios added that he's prepared for this fight like he's going to slug it out against a prime Pacquiao, who was an eight-division champion in his prime. 

"He's a legend for a reason," Barrios said.

 "He's still dangerous. It's my job to go in there and defend my title. I am expecting the best version of Manny regardless. Maybe, I'm going to be the one who retires him."

Beating a legend like Pacquiao will open more doors for Barrios, who will reportedly earn between $500,000 to $1million in this fight. 

"A name like Manny is huge for my resume," Barrios said.