By Ryan Songalia (photo by Chris Farina/Top Rank)

As Manny Pacquiao ascends the boxing scales with seemingly wanton disregard for size disparities, you have to wonder if - at 150 pounds - "The Pacman" is close to biting off more than he can chew.

Antonio Margarito - his durable nemesis for Saturday's clash at Cowboys Stadium in Arlington, TX - stands nearly five inches taller and has fought in the welterweight and junior middleweight divisions for the majority of his career.

Pacquiao, who won his first world title over a decade ago at just 112 pounds, is seeking his eighth world title in as many weight classes when he challenges for the vacant WBC junior middleweight title.

Margarito, a three-time welterweight champion, is making his second attempt at capturing a title in this division.

Most feel that Margarito (38-6, 27 KO) of Torrance, California by way of Tijuana, Mexico is not the ceiling in Pacquiao's career but rather a hand-picked foil that lacks the necessary speed and career momentum to pull off the upset. Margarito is the third consecutive Top Rank-promoted stablemate that Pacquiao (51-3-2, 38 KO) of General Santos City, Philippines has faced.

It also helps Pacquiao's cause that it's easier to rise in weight than to drop.

The catchweight of 150 pounds - which is four under the normal divisional limit of 154 - is designed to cut Margarito's strength advantage down to size. This is Pacquiao's second straight world title challenge in which his opponent was obligated to come in under the regulation limit (Miguel Cotto, from whom Pacquiao wrested the welterweight title last year, faced Pacquiao with a 145-pound catchweight).

"There's a reason Pacquiao is -650 for this fight," said former junior welterweight champion Paulie Malignaggi, citing the most recent betting odds at the time of print. "I think Pacquiao is going to win. He's too fast, he's better technically and never gets tired."

There are some though, that believe that Pacquiao has handicapped himself by allowing his after-boxing career to affect his during-boxing career.

Pacquiao was elected congressman of the Sarangani Province of the Philippines earlier this year, heaping another lofty responsibility onto his already full plate. HBO, who will televise the event via pay-per-view, has highlighted the distractions that Pacquiao has encountered in training camp, which include a typhoon in Baguio City and an impromptu break in camp to fly to Las Vegas to endorse Senate Majority Leader Harry Reid's (D-Nev.) run for re-election last month.

"I think it comes down to one guy has had the camp of his life and the other has had his worst in years," says MaxBoxing.com's Gabriel Montoya, who has witnessed both men during media workouts in Southern California. "I see in Team Pacquiao a kingdom at its most decadent. Politics, planned post-show concerts, TV show guest spots."

Chino Trinidad, sports director at Filipino TV station GMA 7, has also seen both men prepare in camp. He says he isn't buying the "overblown distraction stories...used to the hilt by HBO."

"I have Pacquiao overwhelming Margarito with his speed and foot movement."

Margarito, who at 32 is a year older than Pacquiao, has fought just once in the past 22 months since being caught with "plaster-like substances" in his handwraps prior to his one-sided loss to Shane Mosley last January.

Margarito looked rusty and out-of-synch in his last fight, which was his first working with new trainer Robert Garcia. The match, which took place in Mexico due to Margarito's suspension in the United States, was against a fighter coincidentally named Robert Garcia.

The suspension could have been a blessing in disguise, however. Margarito, who was knocked out in nine brutal rounds by Mosley, was forced to take a break from boxing and the rest might do him well.

“The time is here and there are no excuses," said Margarito at Wednesday's final press conference before the fight. "I am ready for the fight. I had one of my best camps I have ever had and I am here to show I am back."

Pacquiao, whom HBO commentator Jim Lampley once said looked like he was going to a New Years Eve party on his way to the ring, was all smiles as usual at the press conference, belying the potentially vicious encounter he is about to embark upon.

“I expect a good fight on Saturday night,” Pacquiao said. “He's a very good fighter and he throws a lot of punches and this is what I want. It is going to be fun.”

Pacquiao wouldn't be the first fast southpaw Margarito had beaten before, however.

In 2000, Margarito faced Sergio Martinez in Las Vegas and stopped him in seven rounds. Oddly enough, Martinez is now the middleweight champion of the world. It is interesting to note that three of Margarito's six losses have come to lefties.

Two men who know what it's like to be in the ring with both, at least in the gym, both state that despite the size disparity, Pacquiao has the bigger clout in his fists.

Manny's power hurt more," said Rashad Holloway, who sparred 30 rounds with Pacquiao leading up to this fight. "Manny's not the most technically sound fighter but he's more so than Margarito. When you have a snapping punch coming at you, a punch that you don't see with some speed on it, that's an explosive kind of power that hurts you. That's the kind of power that startles you and can put you down.

"When you have a heavy-handed individual, which is what I consider Margarito, his punches aren't the type that hurt you with one shot but an accumulation of them can put you down."

Welterweight prospect Said El Harrak also heralded Pacquiao's power, adding "he hit me the hardest I've ever been hit and I've been in the ring with cruiserweights."

Holloway, who battles Paranaque City, Philippines contender Dennis Laurente on the undercard, feels that Pacquiao's movement will trouble and befuddle Margarito.

"I'm going with Manny because it's a bigger ring. Margarito is used to a smaller ring and being physical. But Margarito has trouble with movement. He has trouble with good boxers and body shots. He can take a head shot all day.

"If Manny is dumb enough to stand still, then it can go in Margarito's favor. But that's not the game plan."

Still, a desperate fighter is a dangerous fighter. Whatever is left of Margarito's career all hangs in the balance. Unlike Pacquiao, Margarito doesn't have a political, acting or musical career to sustain him after boxing. He's just a fighter. 

Ryan Songalia is a member of the Boxing Writers Association of America (BWAA) and a contributor to GMANews.TV. He can be reached at ryan@ryansongalia.com . An archive of his work can be found at www.ryansongalia.com . Follow him on Twitter at www.twitter.com/ryansongalia .