There's still uncertainty about the fight of the century.

That's because Floyd Mayweather Jr. is yet to sign the fight contract Manny Pacquiao's camp has sent. According to Top Rank CEO Bob Arum, all the terms and conditions of the Pacquiao – Mayweather fight have been sorted out and that everything has been agreed to. They are just waiting for Mayweather to sign the contract.

But if this still doesn't push through, the pound-for-pound king may need to face off with one of his good friends, Amir Khan.

Interestingly, Khan is also awaiting word from Mayweather since there have been talks about the two facing each other in the ring. Now, if the former still doesn't give a response, Khan will have to fight Manny.

The two friends met in London just recently after Pacquiao had dinner with Prince Harry, who is a huge boxing fan, and discussed the possibility of a boxing bout. Bob Arum said in a tweet that Manny is willing to do the fight in Amir's native England.

"Yes, there's a big possibility, nothing personal, we're just doing our job in the ring. It's not difficult for us because we respect each other and we're just doing our job in the ring," Pacquiao says about facing off with his friend.

A Pacquiao-Khan fight could be a good one, but it's clearly not one most fans are hoping for.

There could still be a chance that the epic fight pushes through because, according to Shane Mosley, Mayweather has indicated he'll be retiring after two more fights and he wants a bout that will give him the biggest revenue before he bids goodbye to boxing.

A Pacquiao fight is the one that has the most potential to earn Mayweather a lot of money, so that could be what he's waiting for.