Legendary boxing world champion Manny Pacquiao recently commented on UFC star Conor McGregor and the subject of MMA fighters challenging pro boxers.

Combat sports come in different shapes, but the most famous of all is boxing. However, mixed martial arts is now also being  recognized. With boxing still in fact the biggest combat sport in the world, this could be one of the reasons why more and more MMA fighters are calling out pro boxing champs.

The most popular MMA vs. boxing event was indeed the Mayweather vs. McGregor fight. The sold out fight seemed to have given more MMA fighters hope that they could stand a chance against world boxing champs. However, Pacquiao had a different point of view regarding the issue.

In brief interview with ESPN in his own home, Pacquiao addressed two important things in boxing. First, he touched on the possibility of him and nemesis Floyd Mayweather Jr.'s talked-about rematch. According to Pacquiao, the question of whether or not it is really possible for a rematch to happen is something Mayweather has to answer.

Pacquiao said that as far as he is concerned, he is still active and available to fight anytime as opposed to Mayweather who has not fought in boxing since stopping McGregor in 2017. But regardless of what the undefeated champ wanted to do in his career, Pacquiao clarified that he will always be open for another showdown.

"If he coming back and decided to fight me, I'm here," Pacquiao said.

Manny Pacquiao WBA welterweight champion Manny Pacquiao looks on during a news conference at MGM Grand Hotel & Casino on January 16, 2019 in Las Vegas, Nevada. Pacquiao will defend his title against Adrien Broner on January 19 at MGM Grand Garden Arena in Las Vegas. Photo: Getty Images/Ethan Miller

As for MMA, Pacquiao had an interesting point to share. The eight-division title holder believes that MMA and Boxing is "different," and "stamina" is what makes boxing a bit more difficult.

"MMA and boxing is different, especially boxing. In boxing if you don't have enough stamina, you'll be in trouble," Pacquiao noted.

Pacquiao also believes that both McGregor and Mayweather are good fighters but an MMA fighter, which is McGregor will have an advantage if he had faced Mayweather in MMA.

"They both can compete but the thing is it depends what arena they're going to fight. If you're going to fight in mma rules the mma fighter has the advantage," Pacquiao said.

Just a few days ago, Pacquiao's trainer Freddie Roach revealed who Pacquiao wants to fight next should the fight against WBA welterweight regular champ Keith Thurman will be a success. And according to Roach, it's not a fight with Errol Spence or Terrence Crawford but a rematch with Mayweather.

Conor McGregor and Floyd Mayweather Conor McGregor and Floyd Mayweather are seemingly not on good terms just over a year from their boxing fight. In this picture, Mayweather (R) punches McGregor during their fight at the T-Mobile Arena in Las Vegas, Nevada, Aug. 26, 2017. Photo: JOHN GURZINSKI/AFP/Getty Images