By Edward Chaykovsky

For most of 2016, there were countless headlines being generated for a fantasy fight between former five division world champion Floyd Mayweather Jr. and UFC superstar Conor McGregor.

Mayweather, who retired from boxing in September 2015, is open to the idea of fighting McGregor in a boxing match - if UFC President Dana White can offer up a guaranteed purse of $100 million.

White didn't come close to Mayweather's monetary demand. Two weeks ago, the UFC executive offered Mayweather a guarantee of $25 million.

Mayweather laughed at White's offer and called him a "f***ing comedian." The retired superstar made a reported $300 million for his May 2015 mega-fight with Manny Pacquiao. Even in his final career fight against Andre Berto, Mayweather was guaranteed $32 million.

McGregor is very serious about the fight. Last November, he secured a boxing license in the state of California. But the UFC has him under an exclusive contract - which prevents him from pursing a boxing match without their involvement.

For his part, Pacquiao is not taking the Mayweather-McGregor headlines seriously. He believes the two fighters are just talking smack to generate press.

“I don’t know if they are taking it seriously. It’s on the news but I don’t know if it will happen,” Pacquiao told Fox Sports.

And if Mayweather-McGregor does happen, Pacquiao gives the MMA fighter no shot to win.

Like his career rival Mayweather, Pacquiao is also open to the idea of fighting McGregor - if the money is right.

“In boxing? In boxing [I would fight McGregor] but not in [UFC], just boxing,” Pacquiao said.

Last year, some sparring footage was leaked where McGregor was struggling and getting worked over by welterweight contender Chris Van Heerden of South Africa.

While Pacquiao never saw the footage, he's not surprised that McGregor struggled.

“I didn’t see it [footage of Conor sparring]. But if we are talking about Conor McGregor and boxing, it’s different. Boxing is different than MMA," Pacquiao said.

Pacquiao is slated to return to the ring on April 22, against 2012 Australian Olympian Jeff Horn.