Evangelista "Cyborg" Santos' mixed martial arts career has ended after 20 years.
Cyborg announced his retirement in an interview with Guilherme Cruz of MMA Fighting on Monday.
"I'm feeling really well, never felt anything (after the surgery), but I don't think I will fight again," Santos said. "I don't want to risk getting an aftereffect for the rest of my life and don't be able to pass on my knowledge, and give work to my family."
At 39 years old, Santos walks away from MMA with a career record of 21-18 with 12 wins by knockout. He headlined a Strikeforce event in January 2011 against Nick Diaz for the welterweight championship, losing by submission in the second round.
In 2016, Santos transitioned to Bellator. He had three fights with the promotion from April through July, winning his debut match against Brennan Ward before being knocked out in back-to-back fights against Saad Awad and Michael Page.
Despite his recent string of bad luck, Santos told Cruz he had every intention of returning to the cage: "My plan was to fight again this year, and fight 10 more times in MMA, but not everything goes as we plan."
Santos had to undergo surgery in July to repair a broken skull he suffered during the loss against Page after taking a flying knee to the head in the second round.
Even though Santos couldn't reach the top of the mountain in his career, losing all four of his title fights in three different promotions, he was a valuable utility man who was willing to take on all challengers and fought at three different weight classes in his career.