Tito Ortiz, one of the UFC's biggest stars and the record-holder for most fights under the promotion's banner (27), fought three times in 2011. On July 2, he scored an upset first-round submission over light heavyweight contender Ryan Bader at UFC 132. While things started looking up for the one-time "Huntington Beach Bad Boy," Ortiz followed that up with a second-round TKO loss to Rashad Evans just over a month later at UFC 133 on Aug. 6. He dropped another fight at UFC 140 when Antônio Rogério Nogueira beat him with a first-round TKO. Now Ortiz's future with the UFC is in doubt. The 36-year-old has one fight left on his contract, but UFC president Dana White refused to guarantee he'd honor it.
 

Penn is the second fighter in UFC history to win titles in two different weight classes: welterweight and lightweight (Randy Couture was the first). He's one of the true pioneers of the sport and was a mainstay on most pound-for-pound lists for a long time. But by the end of 2011, Penn put his career on hold after he was dismantled in the UFC 137 main event by Nick Diaz. After the bloody battle, Penn wondered aloud if he'd ever fight again, and he's currently taking some time off. One of the greatest UFC fighters of all time is apparently on the verge of calling it quits.

Randy Couture, the first UFC fighter to win titles in two weight classes (heavyweight and light heavyweight), was one of the promotion's biggest stars ever. He held a title five times and fought in 15 title bouts. But "The Natural" saw his career come to an end at the age of 47 at UFC 129 on April 30. After being knocked out by a jumping front kick from his opponent, Lyoto Machida, Couture called it quits on his storied career.

Diaz was supposed to face UFC welterweight champion Georges St. Pierre at UFC 137 on Oct. 29 in Las Vagas, but Diaz failed to show up to media appearances in the months leading up to the fight, forcing UFC president Dana White to yank him from the main event. Diaz's headline spot was instead given to Carlos Condit. St. Pierre later injured his knee, so Diaz fought B.J. Penn in the UFC 137 main event. Eventually, Diaz was supposed to face GSP at UFC 143, but a more severe knee injury to St. Pierre put that on hold, too. Instead, Diaz will face Condit for the intertim welterweight title.

Welterweight champion Georges St. Pierre began 2011 as one of the UFC's true crossover stars, appearing in commercials while maintaining his title with a win over Jake Shields at UFC 129. But after his fight with Nick Diaz was called off, a knee injury postponed his fight with Carlos Condit scheduled for UFC 137. Later, a rescheduled bout with Diaz was slated for UFC 143, but a blown knee put GSP on the shelf again, this time for as much as 10 months. In the meantime, Condit and Diaz will square off for an interim welterweight title without him.