Roy Nelson stuck between a Shane and hard place

After Shane Carwin pulled out of their UFC 125 bout with a back injury, Roy Nelson Jr. was left in a tough spot. He didn't have an opponent for a bout just over two months away. What's a big man to do? How about calling out a smaller opponent who made a throwaway comment about fighting at heavyweight?

Calling out Quinton "Rampage" Jackson may seem extreme, but Nelson doesn't have many choices on who will fight him. The UFC is nowhere near as deep at heavyweight as they are in other weight classes, meaning that they have a limited pool of fighters to pick a replacement from.

The pool gets smaller when you take a close look at the UFC heavyweight division, and see that most fighters fall into two groups: former title contenders or up-and-comers. Nelson is a winner of "The Ultimate Fighter," but at the same time, he is an incredibly experienced fighter. He is also coming off of a loss to Junior Dos Santos.

Obviously, Jackson is a bit busy getting ready for his UFC 123 bout with Lyoto Machida. Medical suspensions, injuries and timing are also working against Nelson. Frank Mir fought in late September. Antonio Rodrigo Nogueira is still rehabbing a knee injury. Brendan Schaub, who has three wins since losing to Nelson in the TUF finale, is still on a medical suspension from his UFC 121 win over Gabriel Gonzaga. Who do you think should fight Nelson?

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