5 of the greatest fighters to never fight in the UFC

Since its inception in 1993, the UFC has asserted itself as the world's most prestigious combat sports promotion. The name value, exposure, and glory athletes garner as UFC competitors are unmatched. Anyone who has ever thought about fighting has likely pictured themselves in the center of the Octagon.

Mixed martial arts's global popularity and demand have led to a proliferation of rival promotions to the UFC. Skilled fighters battle in these outside organizations and sometimes even prove themselves to be amongst the best in the world.

At some point or other, almost every big name in MMA has competed in the UFC. The UFC has been known to acquire champions from their rival promotions and put them up to the test against their top talent. Sometimes, these fighters are on the older side by the time they get to the UFC and consequently flop. Other times, they go on stellar runs and add another title to the trophy case.

Unfortunately, some great fighters never got to compete in the Octagon. These combatants slip through the cracks for many reasons, including bad timing, regional constraints, and contractual disparities.

Here are five fighters who never had the opportunity to test themselves in the UFC.

5. Shinya Aoki

Shinya Aoki (48-11) makes a career collecting submissions across his native Japan's regional MMA scene and Asia's major promotions. He has 31 tapouts as of writing, claiming the likes of UFC champions like Eddie Alvarez and legends like Kazushi Sakuraba along the way.

The two-time ONE FC lightweight champion got his start in martial arts first by earning a judo black belt. He moved on to Brazilian Jiu-Jitsu after gravitating more toward ground fighting rather than stand-up grappling and throwing. This eventually led to Aoki's professional MMA debut in 2003 with the Japanese regional promotion DEEP.

Aoki's aggressive submission game eventually garnered interest from organizations like SHOOTO, PRIDE, and DREAM. He collected a slew of titles, including the DREAM lightweight championship. The 40-year-old's longevity is impressive, as he currently competes as a grappler and mixed martial artist in ONE FC.

Most of Aoki's career has been spent in Asia, but he has competed for Strikeforce and Bellator, losing to Gilbert Melendez and in his rematch with Eddie Alvarez respectively. Aoki's overall body of work across MMA is impressive nonetheless, considering his wins over John Lineker, Caol Uno, and George Sotiropoulos.

Aoki's submission game is elite and versatile, but he excels in leglocks. His specialty heel hook variation has come to be known as the "Aoki lock" within the submission grappling community.

UFC fans have unfortunately never seen Aoki work his submission wizardry in the Octagon. Given the fact Aoki is a massive star in Asia, it makes sense for him to stay close to his fans while facing top-tier competition in places like ONE FC. Aoki has competed for ONE since 2012 and has achieved great success, remaining competitive far past the age most fighters severely decline.