[5] Frank Mir was riding a three fight win streak leading up to this event, including a submission victory over Antônio Rodrigo Nogueira, a friend and mentor of Junior dos Santos, at UFC 140.

On April 4, 2012, however, the Nevada State Athletic Commission (NSAC) announced Overeem had failed his pre-fight drug test.

[12] On April 20, 2012, UFC President Dana White announced that Junior dos Santos would now defend his title against Frank Mir instead.

[13] Two days later, White announced Cain Velasquez (who was originally slated to fight Mir in the co-main event) would face Antônio Silva.

[14] Roy Nelson (who was originally scheduled to fight Silva, and then briefly Gabriel Gonzaga)[15] faced Dave Herman.