Floyd Mayweather needs to fight Manny Pacquiao. Manny Pacquiao needs to fight Floyd Mayweather, but not quite as much. It's not fair, but that's how it is.
As we anxiously await news from the mediation proceedings between the Pacquiao and Mayweather camps the stakes are enormous on both sides, yet they're not exactly the same. The fighters are at different points in their careers and lives and these factors mark the fight as far more crucial to Floyd Mayweather's legacy and future than Manny Pacquiao's. Let's look at a few factors:
Money: I'm not talking about Mayweather's handle; I'm talking about the actual green stuff. Despite what some might say this is always the most important issue. While Floyd has made an enormous amount of money in his career he also has an outrageously expensive lifestyle. Whether the multiple reports of Mayweather's tax problems and investment losses are entirely true, it's hard to imagine there is not some substance there. His huge entourage and gambling habit are hard to maintain, and if the reports are accurate he needed the Marquez fight just to get his head above water. The potential forty million he could gain fighting Pacquiao dwarfs every other possibility.
Manny has a similarly large entourage and I don't doubt that his spending habits are probably not the most prudent. However, it's a lot cheaper to live in the Philippines and play pool with friends than to do the same in Las Vegas. Pacquiao can't make as much elsewhere, but he's also not the one with "money" as part of his name and persona.
Legacy: In some ways it is unfair for Mayweather that he has always been thought of so highly that none of his feats in the ring were seen as all that impressive. He is perceived, rightly or wrongly, as having avoided the biggest challenges. We can debate this all we want and some of it isn't his fault - such as Tszyu and Judah losing before he got a chance to face them at their best - but Mayweather has never had to slay his monster. There has never been that one fighter that people thought was a bridge too far. He has had a tax put on his resume based on his consistent excellence.
Manny Pacquiao has already cut through a legion of challenges people thought too difficult: Barrera, Morales, Marquez, De La Hoya, and Cotto. That he was doubted along the way only serves to magnify his accomplishments. In many ways the victory over Cotto was the final seal on his greatness. It gave him a record setting belt in his seventh division and a victory over a bigger fighter in his prime. There are no doubts about Pacquiao's willingness to take on the biggest challenge and overcome long odds. He has been blessed with more impressive opponents.
Options: Mayweather is trapped. His last fight against Marquez, which I found impressive, is largely seen as a monstrosity at this point. Many people, even fans, felt cheated and insulted by the event. Marquez was the smaller man, as was Mayweather's previous opponent, Ricky Hatton. By the next time he steps into the ring it will have been nearly three years since he will have faced a man his size. I've recently heard the name of Paulie Malignaggi as a potential Mayweather opponent, but that simply isn't feasible. A borderline top-five junior welterweight with no power isn't enough for the fans at this point. He needs a big fight and he needs one right away. The only other option is Shane Mosley, and if Floyd's previous comments are any indication he doesn't seem particularly eager to take that fight at this moment.
As for Pacquiao, the name most likely is Yuri Foreman. It's not a great fight, but the junior middleweight opponent at least offers some historical relevance; a belt in another division. Additionally, Pacquiao has earned himself some leeway. His recent string of victories has been impressive and the fans and HBO are likely more willing to give him a break than Floyd Mayweather.
Public perception: If Mayweather has won the media battle on performance enhancing drugs he might have lost the overall war. Mayweather's insistence on unprecedented testing has led as least some to call him a prima donna, or, even worse, scared. Ultimately Mayweather's perception will be formed by who he fights. Malignaggi just won't cut it and he will be the big loser if that fight takes place.
Pacquiao has taken a major blow to his reputation. Whether fair or not, a good percentage of the general American sports fan now views him as suspect. It's clear that Pacquiao realizes this; his defamation lawsuit shows that he takes it seriously. However, what many American fans and media don't seem to realize is that Pacquiao is not an American. He is a Filipino and still beloved and trusted in his home country. While he's doubtlessly disturbed by this talk he has a loyal group still fully behind him.
While both fighters need this match, and most importantly, the sport of boxing needs it, Pacquiao ultimately has more residual strengths to storm the criticism if the fight falls through.