5 of the greatest fighters to never fight in the UFC

4. Ricardo Arona

Ricardo Arona (14-5) is one of the most feared and prolific grapplers in MMA history. His legendary runs through the RINGS tournament and PRIDE FC in the early to mid-2000s establish him as one of the most elite talents to bypass the UFC's clutches in history.

Arona competed with and beat some of the best of his era, including Jeremy Horn, Guy Mezger, Dan Henderson, Wanderlei Silva, and Alistair Overeem. All those men had successful careers in the UFC, so there's no questioning the quality of competition Arona dismantled over his brief run.

BJJ was Arona's base, and he was a decorated submission grappling competitor as well. His dominance in the Abu Dhabi Combat Club submission fighting championship saw him collect an overall 13-0 record in the competition with titles in 2000, 2001, and the super-fight championship in 2003.

Arona did his best work in PRIDE FC but unfortunately didn't join the UFC when the promotions merged in 2007. A laundry list of injuries forced the then-31-year-old to take a sabbatical from MMA. He fought once more in 2009 and beat Marvin Eastman, but recurring knee injuries forced him to shelve his fight career for good afterward.

Unfortunately, Arona's legacy hasn't received as much recognition as it deserves due to its brevity and the fact he never tested himself in the Octagon. However, he faced and overcame a brutal string of fighters, compiling one of the best resumes of his respective era. Had Arona not been derailed by injuries, there's no telling how high his UFC ceiling could have been.