This is one of those rare times when a man has the opportunity to show if he’s learned from his past mistakes. This is one of those times when we’ll learn if Bob Arum is who he says he is, or at least who he said he should have been long ago.

When Arum, one of boxing’s greatest promoters, was inducted into the International Boxing Hall of Fame in 1999 he took himself and his long-time rival Don King to task for the way they had done their business in recent years. He said they had become part of the problem in boxing because their thinking was too often short term and most often fixated simply on making the most money rather than acting for the good of the sport that had made them both millionaires.

Boxing is the only sport that has no one looking out for it. There is no David Stern, no Roger Goodell, no commissioner of any sort with final say over anything. It is and always has been the Wild, Wild West. At times that is part of boxing’s charm but as it more and more slipped into second class citizenship on the sporting landscape the reasons why were many but one of the most damning was that, as Arum said that day, boxing’s most influential men too often acted in ways that did not help or honor their sport.

This brings us to Manny Pacquiao’s next opponent.

Assuming that is not Floyd Mayweather, Jr., the best fight from the sport’s perspective is a third one with Pacquiao’s long-time nemesis, Juan Manuel Marquez. That is frankly beyond dispute, even by Arum if he’s feeling honest.

They fought twice, in 2004 and 2008, and both were brilliant displays. The first ended in a draw. The second ended with a split decision going to Pacquiao. Both results were controversial and there are many knowledgeable boxing people who believe Pacquiao has yet to beat Marquez, which would only add to the allure of a third fight at a time when Marquez is aging at 37 and Pacquiao appears to be at the height of his powers.

Marquez reasserted his right to that third fight by stopping Michael Katsidis last week six months after undressing Juan Diaz. Both fights were for the lightweight title, but even thought Pacquiao now fights around the welterweight limit of 147 Marquez said immediately that, “Obviously, Pacquiao is my priority. I’ll go up to 140 (to fight him). It’s no problem.’’

No, Arum is the problem.

Pacquiao said in Manila he was willing to do a third fight but then downplayed the possibility, claiming fans might not be interested. Who is he kidding?

Arum knew better than that so he’s saying the problem with that fight is only boxing fans want to see it and he’s looking for something bigger. Then he mentioned Andre Berto and Shane Mosley and blew that position.

“Look, Marquez is a wonderful fighter,’’ Arum conceded, “but the casual fan doesn’t know Juan Manuel Marquez from Juan Manuel Lopez.’’

They don’t know Andre Berto from Andrei Sakharov either. Which one plays piano again? Andre Berto or Andre Previn?

Under that argument then Arum is left with a 39-year-old, fast fading Shane Mosley, who never could draw even when he was the best lightweight in the world and the two-time conqueror of Oscar De La Hoya. Arum is arguing that the casual fan knows Shane Mosley. Perhaps but if so most of the time they haven’t been willing to pay to watch him.

That fact is compounded by another – Mosley is 0-1-1 in his last two fights, one a dreadful beat down at the hands of Mayweather and the other an unwatchable, boring draw with Sergio Mora. If a fight is made with Pacquiao next spring it would have been more than two years since Mosley last won while Marquez is coming off two straight wins, has won eight of his last 10, his only defeats coming against Mayweather, who was simply too big for him, and by split decision to Pacquiao.

Of the three, you tell me, Bob, which fighter has EARNED the fight?

Of the three, you tell me, Bob, which fighter truly deserves the fight?

Of the three, you tell me, Bob, if Berto is better known than Marquez or if Mosley has a snowball’s chance in hell of winning?

Arum has said he needs only two numbers from the three fighters – what guarantee they’re looking for and how much per home above a certain number they want to sign – to make a decision.

Antonio Margarito, Pacquiao’s last victim, had a $3 million guarantee and earned $3 per home over 700,000 buys. When Marquez fought Mayweather he received a $4 million guarantee but got only $1 a home for everything above one million buys. What that tells me is a financial deal is doable unless Arum doesn’t want any part of having Pacquiao face the many problems Marquez poses.

Then there’s the issue of weight. Arum is insisting the fight be at 147 pounds, the welterweight limit, even though in Pacquiao’s last fight he refused to allow Antonio Margarito to fight at the super welterweight limit of 154 even though that was the title they were allegedly fighting for.

That left him struggling to make 150 and a landing strip for Pacquiao’s punches.

The fact is Marquez is best at 135 pounds and certainly is no welterweight, as Mayweather taught him. Pacquiao, on the other hand, weighed 144 ½ for the Margarito fight and could easily make 140 if he wanted to. That is the fair weight and it would not benefit either of them. It would be what boxing seldom is these days – a level playing field.

“The weight is 147,’’ Arum said recently, “because I’m sick and tired of the weight discussions when it’s not to his benefit.’’

How about what’s to boxing’s benefit? How about what’s the right thing to do? How about giving the guy who has EARNED the fight by his performances getting the fight instead of a guy who hasn’t won in two years or a guy who has yet to fight a single top shelf opponent?

In the end, that decision will be made by Pacquiao but if Arum really meant what he said at his Hall of Fame induction in 1999 this is an opportunity to back it up with his actions. He can’t make Manny Pacquiao grant Juan Manuel Marquez a well-deserved third fight but he can certainly urge him to do so and make those feelings known.