According to MMA Junkie, Fukuda has been released as a result of testing positive for several "banned stimulants," while Caceres will serve an extended suspension due to a positive test for marijuana metabolites:
Fukuda tested positive for banned stimulants (phenylpropanolamine, norpseudoephedrine and ephedrine), and Caceres was flagged for marijuana metabolites.
UFC on FUEL TV 8 took place March 3 at Saitama Super Arena in Saitama, Japan. With the lack of a regulating body in place, UFC officials oversaw the drug testing at FUEL TV-televised event.
Caceres had previously won a close bout with Kyung Ho Kang at UFC on Fuel 8, which marked his third-straight win at 135 pounds.
However, his positive drug test will see that win for "Bruce Leeroy" turned to a no-contest decision.
Fukuda isn't nearly as lucky, though, as he previously posted news of his release from the UFC on his Twitter account, thanking the promotion and training partner Jon Fitch for his 2-3 stint in the promotion.
Through his five fights in the UFC, Fukuda had never put together a winning streak and lost his last fight to Brad Tavares via unanimous decision.
As MMA Junkie notes, this marks another string of positive drug tests for UFC fighters, as Caceres and Fukuda join Matt Riddle, Thiago Tavares, Rousimar Palhares, Thiago Silva, Stephan Bonnar, Jake Shields and Lavar Johnson on the list of prominent MMA athletes outed for banned substances.
Update: According to MMA Fighting, Riki Fukuda was apparently set to be cut from the UFC following his loss to Brad Tavares.
UFC director of regulatory affairs Marc Ratner tells MMA Fighting that Fukuda's release was "more a coincidence" than anything else. He also commented on Alex Caceres' penalty, noting that the young bantamweight will be required to attend rehabilitation classes with a final drug test to complete his suspension.
McKinley Noble is an MMA conspiracy theorist and tech writer. His work has appeared in GamePro, Macworld, PC World, 1UP, NVision, The Los Angeles Times, FightFans Radio, MMA Mania and Bleacher Report. Talk with him on Twitter.