Former middleweight champion Anderson (The Spider) Silva has been pulled from a Nov. 25 UFC card in China for a potential doping violation dating back to an Oct. 26 out-of-competition sample.
The UFC said it has removed the 42-year-old Brazilian from the Shanghai card and is looking for a new opponent for American Kelvin Gastelum.
Silva, considered a mixed martial artist legend, won 10 consecutive title defences over seven years as the UFC's 185-pound champion until losing the belt to Chris Weidman in 2013.
He was suspended for one year in August 2015 after testing positive for steroid use.
The Nevada Athletic Commission stripped Silva of his UFC 183 win over Nick Diaz and fined him US$380,000. The fight, which was changed to a no-contest, marked Silva's return to action after 13 months sidelined by a badly broken leg.
The commission said Silva (34-8-0 with one consistent) provided inconsistent testimony and records after testing positive for Drostanolone metabolites.
Silva, ranked eighth among 185-pound contenders, wasn't the only UFC fighter to fall afoul of the U.S. Anti-Doping Agency on Friday.
The UFC said American featherweight Grant (The Prophet) Dawson had been notified of a potential violation from an out-of-competition sample collected on Oct. 18.
The Canadian Press