A few months ago, when news broke that Conor McGregor and Floyd Mayweather would be stepping into the boxing ring to go head-to-head, many people couldn’t believe it. Sure, both men are professional fighters, but boxing and MMA are two totally different beasts.

However, the hype surrounding the fight made it one of the biggest sporting events of the year, and it looks like athletes challenging athletes from other sports might just be the new thing to do.

Well, it looks like Michael Phelps is the latest professional athlete to challenge someone from another sport to compete against him, and his opponent of choice is none other than Conor McGregor.

Apparently, Phelps wants to take it to the pool and race McGregor – and he’s letting it be known.

Continue to page 2 to see Michael Phelps tweet calling out Conor McGregor…