LAS VEGAS >> Manny Pacquiao acts as though it’s personal, then claims it’s not. Just another night in the ring, another notch on his belt and another $25 million or so to take back to the Philippines with him.

It’s not that easy for Juan Manuel Marquez. He remains convinced he won both of his previous two fights with Pacquiao, and he will enter the ring Saturday night as eager for redemption as he is to claim the biggest payday of his long boxing career.

"I hope the judges score what they see, not like the other two fights when they were not impartial," Marquez says.

The judges may not be necessary this time around. Marquez has bulked up for the 144-pound fight so he can bring more power into the ring and Pacquiao — who knocked Marquez down four times in their two fights — is a far more potent puncher than the last time they met three years ago.

Add in the fact these two fighters throw punches almost nonstop, and there’s potential for an early ending.

"I’m not thinking about the knockout," Pacquiao said. "If the knockout comes, that’s just the bonus for your sacrifices in training."

Pacquiao returns to the ring for the first time since he beat Shane Mosley in May, fighting a familiar foe in a bout that will earn him yet another big payday. He and Marquez have already gone 24 rounds with each other, rounds so close that ringside judges had trouble figuring out which fighter won.

But the first fight seven years ago was at 125 pounds. The second four years later was at 130 pounds.

This one will be for a piece of the welterweight title, though it will be at a catch weight of 144 pounds. It’s a weight Pacquiao has proven comfortable with over the last few years, but Marquez had no success the only time he got past 140 pounds in a lopsided loss to Floyd Mayweather Jr.

That’s the big reason Pacquiao is a 7-1 favorite in a pay-per-view fight that doesn’t figure to lack for action.

"At 144 pounds it’s going to be different," Pacquiao said. "I’ve improved my boxing and my power. Everything is going to be different."

Pacquiao weighed in at 143 pounds Friday, while Marquez was 142 — the same weight he fought at against Mayweather.

Pacquiao — who last lost in 2005 at 130 pounds — risks a 14-fight winning streak against Marquez, a Mexican who has held titles in three different weight classes. Once again he will carry the weight of the Philippines into the ring, and once again he will be fighting someone other than Mayweather.

That’s hardly Pacquiao’s fault, though, since Mayweather doesn’t seem serious about fighting him. So he has to make do with other contenders, and Marquez has better credentials than any of Pacquiao’s opponents since he made a name for himself by sending Oscar De La Hoya into retirement in 2008.

In their first two fights, Marquez used his superb counterpunching skills to keep Pacquiao off balance. Though he went down — three times in the first round of the first fight — Marquez was more than competitive in two fights that could have gone either way.

That the first fight was scored a draw and the second a split decision for Pacquiao still gnaws at Marquez, who wore a T-shirt proclaiming he was robbed in both fights when the two boxers were in the Philippines promoting the bout.

That touched a nerve in Pacquiao, though he said this week that there is nothing personal between them.

"He went to the Philippines wearing a T-shirt saying ‘I beat Manny Pacquiao twice,’" Pacquiao said. "I’m not angry. That’s his freedom to do that."

Still, trainer Freddie Roach said there was an added urgency to Pacquiao’s training camp for this fight. The jokes and clowning around from previous camps were gone, with Pacquiao training in quiet determination. Roach says Pacquiao wants to settle the issue once and for all.

"I think it was a slap in the face to Manny," Roach said. "They were both good, close fights, but there were no robberies there."

Pacquiao said he has learned since his last fight with Marquez how to fight a counterpuncher. He’s also improved greatly with his right hand, which at lighter weights he never seemed to be able to land with much power. And he says he’s taken the lessons learned in his first two fights with Marquez to heart.

"The last two fights helped me a lot," Pacquiao said. "I learned a lot, especially fighting a counterpuncher, a boxer. I’m more experienced now and I’m a much better fighter, too."

Marquez turned to a new strength and conditioning coach to add weight and power for his move up from 135 pounds, though that hasn’t been without controversy. The coach, Angel Heredia, was a government informant during the BALCO investigation. He and Marquez both say he has taken nothing but legal supplements to prepare for the fight.

Still, some in boxing are shocked at the new physique of Marquez, while others are shocked that he tried to gain so much weight rather than using his speed and counterpunching ability to fight Pacquiao this time around.

"He’s bigger, bulked-up and slower," Roach said. "When Manny puts him down this time I don’t think he’s going to be able to get up from the way this Manny Pacquiao punches."