It's easy to forget in amongst the Floyd Mayweather/Conor McGregor sideshow that the latter is still a UFC champion.In fact, the UFC lightweight champ is the company's biggest draw by a long, long way and the world of MMA is eagerly awaiting his return to the Octagon.But, who will it be against?Fans are clamouring for McGregor and Nate Diaz to tie a bow on their rivalry and have their trilogy fight and considering their first two bouts ranks in the top three selling pay-per-views in the UFC's history, chances are the company want that one to happen.However, and quite unbelievably so, despite being a two-weight and briefly simultaneous champion in the UFC, McGregor has never defended one of his titles.Surely that has to change and with Tony Ferguson defeating Kevin Lee for the interim lightweight title at UFC 216, it looks like McGregor and Ferguson has to happen even if it isn't the most lucrative fight available.And UFC president Dana White agrees:

Furthermore, White has revealed that McGregor told him he wants to fight again before the end of the year and previous reports have suggested that a bout in December seems the most likely.

For what it's worth, McGregor thinks Diaz is trying to make the most out of his name if they lock horns again and he is happy to prove people wrong by actually defending his title.

"Diaz is there, Nathan is there. He's sitting there," The Notorious said at a Q&A session in Glasgow last month. "He's trying to come in and make all these kind of demands.

"But if he starts pricing himself out of an event, then I probably will defend against the winner of this interim belt or someone along that line to kind of legitimise it again.

"I've already gone from the highest of the high in terms of a money fight. Now the question I always get is about defending the belt and legitimising the sport and the rankings.

"Maybe now it would be a good time for me to go do that and shut that side up."