When it comes to discussing Mixed Martial Artists and retirement the conversation tends to be on fighters who have held on a little too long a la Jens Pulver, Chuck Liddell, or Tito Ortiz. However, there are plenty of pugilists who have walked away from the UFC with gas left in the tank to the chagrin of countless fans. Here’s a look at five competitors whose time in the Octagon was cut short… (Photos by USA Today Sports Images)