Will Juan Manuel Marquez and Manny Pacquiao go another round?

Juan Manuel Marquez is making an argument that’s impossible to buy.

Twice, the top Mexican fighter in the world has fought Manny Pacquiao — the first time in 2004 was a draw, the rematch in 2008 was a split-decision loss that Marquez’s camp bitterly protested.

No one else comes close to Pacquiao now. Not the 17-pounds-heavier Antonio Margarito, not junior-middleweight world champion Miguel Cotto — and the reclusive Floyd Mayweather Jr. isn’t willing to let us learn.

So how can Marquez honestly sit there in his spot as the world’s third-ranked pound-for-pound fighter and say he’s not obsessing about getting a third fight against Pacquiao?

“Maybe you don’t believe me,” said Marquez, 37. “I’m being honest with you.”

Pacquiao’s career has soared unbelievably since his Marquez matches. He is a no-argument No. 1 in the pound-for-pound debate, has knocked out Ricky Hatton at 140 pounds, stopped Oscar De La Hoya and Cotto at 147 and impressively scored a decision over the battered Margarito on Nov. 13.

Add Pacquiao’s trappings of a seat in the Philippine Congress, a “60 Minutes” interview and a late-night duet with Will Ferrell, and you’d have to be otherworldly not to experience a twinge of envy.

Marquez, meanwhile, will have trouble getting people to show up on Thanksgiving weekend for his Saturday night world lightweight title defense against Australia’s Michael Katsidis (27-2, 22 knockouts) at MGM Grand Garden Arena in Las Vegas.

The HBO card includes a world welterweight title defense by Andre Berto (26-0, 20 KOs) vs. Freddy Hernandez and talented featherweight Celestino Caballero (34-2, 23 KOs) vs. Jason Litzau.

“If the third fight with Pacquiao happens, it happens,” said Marquez (51-5-1, 37 KOs). “I did a lot in my career, and there’s a lot of talent around me. He waited four years to fight me after the first fight, and now it’s going to be three years after the last fight. It’s not up to me, and I’m not desperate.

“I believe I did what I had to do in my career. Economically, I’m in very good shape. I’m going to become a four-division world champion.”

Katsidis has added motivation: He is fighting in memory of his brother, Stathi, 31, a top jockey who was found dead at his home in Australia last month.

Katsidis last week declined to discuss his brother’s death, saying he’s preparing for “a great boxer, puncher, well-conditioned athlete … he’s the best of the best. I am fighting to become the best. It’s a big opportunity I’ve got to take advantage of.”

Best of the best?

“I believe Juan won the first Pacquiao fight, and the worst you could give him in the second fight is a draw. I hold him in high regard,” Katsidis said.

Marquez has been frustrated by the inability of promoters to make a Pacquiao fight. He once paid a visit to the Philippines to urge Pacquiao to fight him. Talks occurred early this year when the first attempt to make Pacquiao-Mayweather failed.

“They turned it down, asking for a 50-50 split and drug testing,” Pacquiao promoter Bob Arum said. “And right after they fought for the second time, Manny had his eyes on bigger fights, which was the right move. The idea that he’s ever ducked Marquez is ridiculous.”

Arum has said Marquez or Shane Mosley would be the top alternatives for Pacquiao should Mayweather remain cool to a super-fight.

Marquez’s case would be boosted by an impressive showing against Katsidis.

“Of all the fighters Pacquiao has fought lately, I’m the only guy who almost knocked him out,” Marquez said. “I hurt him badly, hit him harder than he’s ever been hit. It’s easy for them to mention my name as someone they’ll fight. If it’s that easy, then give me the third fight. Let’s see who’s the best.”

Not that he’s obsessing.

lance.pugmire@latimes.com

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