By Keith Idec

Bob Arum claims that if Floyd Mayweather Jr. genuinely wants to fight Manny Pacquiao that the fight will happen Nov. 13 in Las Vegas.

The hopeful promoter told BoxingScene.com, Yahoo! Sports and SI.com this week that Pacquiao accepted all the proposed terms to meet Mayweather in what would be the biggest fight of the 21st century. According to Arum, Mayweather is in the process of deciding if he’ll oppose Pacquiao for pound-for-pound supremacy or take the rest of the year off.

If fight fans get what they deserve, the top two pound-for-pound boxers in the world will square off in a welterweight title fight that’ll transcend boxing and possibly break pay-per-view and gate-receipt records. But negotiations for a showdown that could earn each boxer at least $30 million inexplicably imploded once, thus there’s no reason to think that these more respectful, quiet talks couldn’t collapse before an agreement is reached.

Regardless, Pacquiao, a newly elected Congressman in his native Philippines, still plans to fight Nov. 13. The prospect of Pacquiao opposing someone other than Mayweather in his next fight is discouraging, but it’s a possibility Pacquiao (51-3-2, 38 KOs) might not be able to avoid.

Arum already has mentioned potential alternatives to Mayweather (41-0, 25 KOs), mostly fighters promoted by his company, Top Rank Inc. His desire to keep all the money in the Top Rank family is understandable, but that might not best serve the paying public.

Below is a look at Pacquiao’s top five possibilities should the Mayweather showdown not materialize:

PROBABLE OPTIONS

1. Pacquiao vs. Antonio Margarito (38-6, 27 KOs, 1 NC)

Why it could happen: Margarito’s size and strength make him a competent option, though Pacquiao’s speed would make the Filipino star a favorite to win. The rugged Margarito also has an 11th-round technical knockout defeat of Cotto on his record, albeit a controversial victory, and Arum is determined to re-establish Margarito as a marketable commodity in the aftermath of his hand-wrapping scandal.

Why it might not happen: The 5-foot-11 Margarito would prefer to fight at 154 pounds, and the 5-6½ Pacquiao won’t fight him any higher than welterweight. If the 32-year-old Margarito decides he can no longer shed those seven extra pounds, Pacquiao will have to seek another opponent. Margarito still isn’t licensed in the United States, either, and there is no guarantee that an American commission will grant Margarito another chance to fight in this country following his despicable attempt prior to his one-sided, ninth-round technical knockout loss to Shane Mosley 17 months ago in Los Angeles.

2. Pacquiao vs. Juan Manuel Marquez (50-5, 37 KOs)

Why it should happen: Marquez has come closer than anyone to defeating Pacquiao since Pacquiao last lost by unanimous decision to Erik Morales in March 2005. Some media members and fans believe Marquez did enough to out-point Pacquiao in their March 2008 rematch in Las Vegas, a very competitive bout that Pacquiao won by split decision. Their first fight ended in a draw six years ago in Las Vegas, so there’s plenty of unfinished business between them.

Why it probably won’t happen: Assuming Marquez can defeat Juan Diaz (35-3, 17 KOs) in their rematch of the 2009 “Fight of the Year” July 31 in Las Vegas, making Pacquiao-Marquez III would require Arum’s Top Rank Inc. and Oscar De La Hoya’s Golden Boy Promotions to co-promote an event. Outside of trying to make Mayweather-Pacquiao again, these rivals seem more reluctant than they were this time last year to work together.

3. Pacquiao vs. Miguel Cotto (35-2, 28 KOs)

Why it could happen: Because Arum needs a Top Rank-promoted option other than the unlicensed Margarito and seems to think that a Pacquiao-Cotto rematch might generate some interest.

Why it should not happen: The first Pacquiao-Cotto fight was not remotely competitive from the midway mark until the time it was stopped in the 12th round. Cotto wasn’t injured during the one-sided fight, and there wasn’t anything abnormal that impacted the outcome. Pacquiao’s speed simply overwhelmed Cotto, and that won’t change if Emanuel Steward or any other trainer is in Cotto’s corner if he fought Pacquiao again. Thus there’s no legitimate reason why Arum should subject fight fans to Pacquiao-Cotto II. It’s about as necessary as a Pacquiao-Joshua Clottey rematch.

PREFERRED OPTIONS

1. Pacquiao vs. Andre Berto (26-0, 20 KOs)

Why it could happen: The Berto-Mosley fight HBO Sports executives hoped to reschedule for the fall won’t happen because Mosley (46-6, 39 KOs, 1 NC) has agreed to face Sergio Mora (22-1-1, 6 KOs) on Sept. 18 in Los Angeles. There aren’t many other welterweights those same HBO Sports executives should pay Berto seven figures to fight at this point, and Berto’s speed could present problems for Pacquiao. Arum claims Berto isn’t ready for Pacquiao. He’s probably correct, but who is?

Why it might not happen: Unless Arum changes his mind about Berto’s readiness and offers Berto so much money that he couldn’t turn down the fight, Lou DiBella, Berto’s promoter, probably will seek other options for his unbeaten WBC welterweight champion.

2. Pacquiao vs. Timothy Bradley (25-0, 11 KOs, 1 NC)

Why it could happen: Bradley’s welterweight debut, a 12-rounder against Argentina’s Luis Carlos Abregu on July 17 in Rancho Mirage, Calif., is partially designed to eventually make him a viable foe for Pacquaio or Mayweather. If Bradley is an undefeated junior welterweight champion with welterweight experience, he would be considered a real opponent for Pacquiao, though a big underdog.

Why it might not happen: Abregu (29-0, 23 KOs) isn’t nearly as good a boxer as Bradley, but he is a big puncher and represents a dangerous test for Bradley in his first fight at welterweight. Obviously, if Bradley loses to Abregu he is out of the Pacquiao sweepstakes.

EDITOR’S NOTES: Even if Paul Williams (38-1, 27 KOs) still can make welterweight, the 6-1 Williams is simply too big for Pacquiao, who is roughly six inches shorter than him. … Theoretically, Devon Alexander (19-0, 12 KOs), Amir Khan (23-1, 17 KOs) and Marcos Maidana (28-1, 27 KOs) are all reasonable possible opponents for Pacquiao in 140-pound title fights or at catch weights, but their promoters (Don King for Alexander; Golden Boy for Khan and Maidana) are less likely to pursue Pacquiao for various reasons.

Keith Idec covers boxing for The Record and Herald News, of Woodland Park, N.J., and BoxingScene.com.