Both Stephan Bonnar and Dave Herman have failed their respective UFC 153 drug tests.
Bonnar tested positive for the anabolic steroid Drostanolone, while Herman tested positive for marijuana metabolites, MMAFighting.com confirmed with Marc Ratner, the UFC's VP of regulatory affairs, who oversaw the drug testing at the event in Brazil, after MMA Junkie first reported the news Friday afternoon.
According to Ratner, the UFC will announce suspensions for both Bonnar and Herman early next week. The other 22 fighters on the card passed their drug tests for recreational and performance enhancing drugs.
Since there isn't an official Brazilian athletic commission, the UFC served as the governing body at the event. Ratner is the former executive director of the Nevada State Athletic Commission.
This marks the second time Bonnar has failed a drug test during his seven-year run in the UFC. He was suspended for nine months by the Nevada State Athletic Commission following his UFC 62 loss to Forrest Griffin in 2006 after metabolites of the anabolic steroid Boldenone were found in his system.
This also marks second positive drug test for Herman while a member of the UFC. He was pulled from his UFC 136 fight against Mike Russow in 2011 after traces of marijuana came up in the pre-fight drug test administered by the Texas Department of Licensing and Regulation.
UFC 153, which was headlined by Bonnar vs. Anderson Silva, was held on Oct. 13 at the HSBC Arena in Rio de Janeiro. Silva defeated Bonnar via first-round TKO, and earlier this week, Bonnar announced that he retired from the sport after an 11-year run.