Manny Pacquiao in the ring has been a selling point for a generation now.

Attempting to become the second-oldest world champion ever, returning from a four-year absence and meeting the most vulnerable of all the welterweight champions adds layers of intrigue to his July 19 battle with WBC welterweight champion Mario Barrios Jnr at MGM Grand Garden Arena in Las Vegas.

“There’s an opening for [Pacquiao],” ProBox TV analyst Paulie Malignaggi said on “BoxingScene Today.” “Eighty percent, even 70 percent [of Pacquiao] beats Barrios.”

At 46, the eight-division champion and June Hall of Fame inductee from the Philippines returned to train with Hall of Fame cornerman Freddie Roach last week, launching a highly compelling camp with the fight date looming against the 30-year-old Barrios, 29-2-1 (18 KOs).

Former Pacquiao foe and ex-140lbs champion Chris Algieri said on “BoxingScene Today” that Pacquiao’s recent flat showing in an exhibition boxing match against a kickboxer likely was the result of “not training at all.

“The Manny Pacquiao I’m seeing in the gym looks a lot better,” Algieri said. “The Manny-Freddie footage … a lot of it is nostalgia – ‘they’re back together! – but on top of the nostalgia, Manny’s got to train.

“At 46, there’s lots of scar tissue to work through and now he’s under the watchful eye of Freddie.”

Algieri floated the question that will sell this fight, as Pacquiao, 62-8-2 (39 KOs), seeks to top George Foreman and trail only Bernard Hopkins in the oldest-ever champion rankings.

“Does he have enough of this Filipino magic?,” Algieri asked and sought to answer after getting dropped six times by Pacquiao in their 2014 welterweight title fight in China.

“Manny Pacquiao is special, the best fighter I’ve ever been in the ring with. There’s no one else like him. He’s way craftier than people give him credit for. It’s not all balls to the wall.”

Maximizing the effectiveness of an aged Pacquiao “is what they’re working on in the lab.”

The concerns are whether Pacquiao “can still pull the trigger” following his 2021 title loss to Yordenis Ugas, and whether he can take Barrios’ best shots, Malignaggi said.

“Barrios gets hit with his hands up or down. What I see is a fight where a lot of punches land because Barrios sucks and Manny’s old. Who can resist for longer?” Malignaggi asked.

Knowing Pacquiao so well and considering his history of three first-round knockdowns in his first bout against Juan Manuel Marquez up to his 2019 sudden knockdown of then-champion Keith Thurman, Aligieri expects the veteran challenger to start fast.

“He’s going to launch it right away,” Algieri said. “If he still has a little of that left, he’s going to crack Barrios. The punch is the last thing to go.”

Malignaggi has long been a skeptic of Pacquiao’s ability to inflate so effectively by natural means only, and said the “800-pound gorilla” is if he performs magnificently at age 46.

Age is the ultimate X factor here.

“If he still has the footwork, he’s got a chance to pull off the upset,” Algieri said. “Barrios is a favorite for a reason – 46-year-old guy, four years out of the ring, didn’t look good in the exhibition.

“It doesn’t matter how this fight starts. Barrios could get cut, hurt, knocked down, but he’s still in the fight. Twelve rounds for a 46-year-old is an eternity and Manny Pacquiao still has to make weight, which is harder as you get older.”

Malignaggi is down on Barrios, who inherited the belt when Terence Crawford moved up to 154lbs, then fought Abel Ramos to a draw in November.

“I don’t know what the guy’s doing here. He should use the right or the right uppercut and work on those defensive liabilities,” Malignaggi said. “I don’t know if he’s teachable.”

Algieri suggested Barrios seek to start fast and stand his ground.

“Both guys are bound to run into some rough moments,” Malignaggi said.

Should Pacquiao endure through his to reclaim a welterweight belt, the greatest boxing story ever told will have the rightful conclusion he has longed for.