Floyd Mayweather Jr. and Conor McGregor have been teasing a potential fight for months, prompting a great debate about who would win in a fight between a boxer and mixed martial artist.  

Manny Pacquiao, who lost to Mayweather in May 2015, appeared on FS1's Undisputed Thursday to give his take on the hypothetical showdown:

If you were to put restrictions on what McGregor could do in the ring, limiting him to just boxing, Pacquiao's prediction would presumably be right, because Mayweather has mastered that one discipline with a 49-0 career mark. 

If Mayweather were to step in the world of mixed martial arts, McGregor would pick him apart, because he can apply more weapons (elbows, knees, grappling) to defeat the undefeated boxing champion. 

Mayweather started this whole discussion with a fake fight poster on his official Twitter in May:

The bigger point to all of this is that McGregor vs. Mayweather is never going to happen so long as McGregor is under contract with UFC. That promotion isn't giving up its biggest drawing card for a one-off boxing match that doesn't benefit Dana White and Co. 

McGregor's coach John Kavanagh also listed a huge obstacle that would stand in the way of the fight during an interview with Ireland's Business Post (via Fox Sports' Damon Martin). 

"There was talk that Conor would get $7 million and Floyd would get the rest of it. It will be an even share, or Conor will not do it," Kavanagh said. "There is no one generating the type of media that Conor is."

Since becoming the biggest star in boxing after defeating Oscar De La Hoya in 2007, Mayweather doesn't give an even split of the purse to anyone. He took home 60 percent of the revenue against Pacquiao in the biggest boxing match of all time. 

Mayweather is a master at marketing and promoting. His initial challenge to McGregor helped give him the publicity he seeks at all times. 

McGregor loves the spotlight as much as Mayweather, so it would be a perfect match just for the promos these two stars would cut on each other. 

It's a shame that so many obstacles are standing in the way of the fight happening any time soon.