The Manny Pacquiao-Floyd Mayweather fight officially has a “sell-by date,” according to new… The Manny Pacquiao-Floyd Mayweather fight officially has a “sell-by date,” according to new HBO Sports President Ken Hershman.

If the fight — which could net each fighter up to $40 million — is not scheduled by early next year, it would become “less than relevant,” Hershman said.

Currently, this fight between the two best boxers in the world only exists within the depths of sporting fans’ imaginations, as the two champs trade verbal barbs and sidestep each other despite expressing interest in the hypothetical bout. While the boxing world has put social pressure on the fighters to set a date, nothing can be done to expedite the situation if the fighters don’t agree on a time, place and dollar amount. Even though it’s been almost two years since the fight has been viable, each boxer insists he wants to make it happen.

Clearly, they don’t mean it.

First, the issue was drug testing. In March 2010, the two sides agreed to fight for $50 million — which they would split — but balked at the idea of Olympic-style drug testing. Pacquiao refused to consent to random blood tests leading up to the day of the fight, instead wanting the blood tests to stop a few weeks before. His promoter, Bob Arum, said that there must be a cut off because drawing blood too close to a fight date could weaken Pacquiao.

More recently, Mayweather has called Pacquiao out — literally and figuratively. First, Mayweather smack-talked his competitor via Twitter and other media outlets. Then he picked up the phone and actually contacted Pacquiao directly to tell the Filipino boxer that he would not agree to a 50-50 split of profits.

“He asked about a 50-50 split, and I told him, ‘No that can’t happen, but what can happen is you can make more money fighting me than you have made in your whole career,’” Mayweather said in an email to SportsCenter. “I also let him know I’m in control on my side, but he needs to get on the same page with his promoter, so we can make this fight happen.”

And that’s when the most lucrative fight in boxing history died — and possibly the sport with it.

To be honest, I don’t actually believe that the sport is going to die, but the argument could be made. These fighters, both on the wrong side of 30, are the top two names in boxing.

Mayweather is an undefeated 42-0 fighter and currently holds the World Boxing Council welterweight (140-147 pounds) title and is a five-division world champion and winner of seven world titles. Pacquiao, 54-3-2 (he hasn’t lost a fight in nearly six years) is currently the World Boxing Organization welterweight champion, the first eight-division world champ and the holder of six total world titles. He was also elected into the House of Representatives in the 15th Congress of the Philippines in May 2010.

Boxing used to reign as the country’s top sport, with its athletes reveling in global attention. With the rise of mixed martial arts and the decline of mega-stars in the sport, boxing needs a fight like this to gain relevance once again. In the past, the greatest champions fought all comers, no matter the purse or opponent. Today, boxers are simply putting money before pride and not vice versa. Boxing’s pulse is dropping, and the Mayweather-Pacquiao fight would serve as the defibrillator, jump-starting the sport and defining the fighters’ legacies.

Mayweather could retire undefeated, and people would say years from now, “Yeah, but he didn’t fight Pac-Man.” Pacquiao could retire to life as a politician and people would ask, “Why didn’t you agree to the blood test?”

Muhammad Ali fought Sonny Liston, Joe Frazier and George Foreman. These two present-day fighters need to shut up and fight each other, for our sake, the sport’s sake and their own sakes.