The hook for Manny Pacquiao's latest fight is that he's the fighting politician, as eager to take on problems in the Philippines as he is to take on other welterweights in the ring.

Unfortunately for Pacquiao, at this stage of his career he needs a hook to sell his fights.

Pacquiao meets a likable but relatively unknown Jessie Vargas on Saturday, with a piece of the welterweight title at stake. In the past that might have been enough to excite boxing fans, but Pacquiao is aging and so is his appeal.

He probably should have retired after not showing up for the biggest fight of his life against Floyd Mayweather Jr. He certainly should have retired after getting elected to the senate in the Philippines, where he's an ally of President Rodrigo Duterte.

Yet he plods on, partly because he reportedly needs the money. He got a few million dollars to fight Timothy Bradley in April but is fighting on percentages against Vargas, so the sales pitch is necessary.

But the fight with Vargas is a tough sell, which is why promoter Bob Arum stacked the undercard with competitive fights and is selling tickets for as little as $50. Arum is also selling the pay-per-view himself after HBO declined to take part in the distribution of the fight, and Pacquiao's purse will largely depend on how well it does.

"Anything north of 600,000 buys would be a big night and he'd make a lot of money," Arum said. "I'm hoping he makes money like the Manny of old."

Arum, of course, is way overestimating what the fight will do, but his job as Pacquiao's promoter is to get people interested. Since Vargas is not well known, it's a difficult sell even with an attractive undercard.

Pacquiao is taking a familiar path for an aging fighter, trying to squeeze a few more fights in before finally hanging up his gloves. He's got the right to fight whoever he wants, but fight fans also have the right to vote with their wallets on the matchup.

The real problem for Pacquiao isn't his opponent, though Arum could have easily put undefeated Terrence Crawford in the ring against him instead of Vargas. It's that he turned off a big portion of his fans in a stinker of a fight against Mayweather and will probably never get them back.

He used to sell a million pay-per-views whenever he stepped into the ring. But he barely sold 300,000 for his fight against Bradley, and this one doesn't figure to do any more.