George Sotiropoulos vs. Takanori Gomi
Coming off of back-to-back losses, George Sotiropoulos was scheduled to enter enemy territory against Takanori Gomi at UFC 144 in Japan.
Sotiropoulos was injured, though, and replaced by Eiji Mitsuoka. Gomi went on to knock out fellow Japanese fighter Eiji Mitsuoka.
Matt Wiman vs. Mark Bocek
Scheduled to fight Mark Bocek at UFC 145, Matt Wiman was injured and replaced by John Alessio. While Alessio got his chance to return to the UFC, Bocek came away with the lopsided decision victory.
Evan Dunham vs. Edson Barboza
Originally, Edson Barboza was scheduled to meet Evan Dunham at UFC 146. However, an injury gave Jamie Varner an opportunity to return to the Octagon by replacing Dunham.
Varner made the most of his chance by beating the up-and-coming Barboza via first-round knockout.
Paul Sass vs. Evan Dunham
In addition to being forced out of a matchup himself, Dunham lost an opponent due to injury for his UFC on Fox 2 appearance.
Paul Sass was replaced by Nik Lentz, who Dunham proceeded to beat by technical knockout due to a cut. While it was a unfortunate ending, Dunham's fight with Lentz was very entertaining and earned him Fight of the Night honors.
Tony Ferguson vs. Dennis Hallman/Thiago Tavares
Tony Ferguson had his opponent changed twice prior to his fight against Michael Johnson at UFC on Fox 3, where he suffered the first loss of his UFC career.
Ferguson's original opponent, Dennis Hallman, was replaced by Thiago Tavares, who also ended up getting injured and replaced by Johnson.
Yves Edwards vs. Donald Cerrone
When Yves Edwards was forced out of his UFC on Fuel TV 3 fight with Donald Cerrone, many thought the UFC had put together an even better fight for Cerrone against slugger Jeremy Stephens.
However, Cerrone dominated Stephens for three rounds and won the fight via lopsided decision.
Paul Taylor vs. Anthony Njokuani
Out of action for more than one year, Paul Taylor was expected to return against Anthony Njokuani at UFC on Fuel TV 4. However, Taylor suffered another injury and has been replaced by Rafael dos Anjos.
Cody McKenzie vs. Michael Johnson
At UFC on Fox 2, Michael Johnson actually benefited from a late opponent change. An injury to Cody McKenzie set Johnson up for a fight with a more respected opponent in Shane Roller.
Johnson won against Roller via decision in a fight that moved him much farther up the lightweight ladder than he would have with a win over McKenzie.
Aaron Riley vs. Cody McKenzie
After being forced out of his fight with Johnson, McKenzie was set to fight Aaron Riley at UFC on Fuel TV 3. Nonetheless, Riley was injured and replaced by Marcus LeVesseur, who McKenzie was able to beat via submission.