According to California State Athletic Commission Executive Officer George Dodd, Chael Sonnen has been notified that he failed post-fight drug screening following his loss to Anderson Silva at UFC 117 , which was held Aug. 7 at the Oracle Arena in Oakland, Calif.“[Sonnen] received his notice yesterday,” Dodd told Sherdog.com shortly after the Shane Mosley-Sergio Mora boxing match ended Saturday night in Los Angeles.In a conversation the day before, Dodd declined to comment on the situation, other than answering that all fighters from UFC 117 had passed drugs-of-abuse scans, but that the commission was still waiting on performance-enhancing drug screens from the event.Dodd did not state which banned substance was red-flagged, but with a clean drugs-of-abuse scan it is clear the positive test was for a performance-enhancing substance.The last major UFC banned-substance case in the state centered on UFC 73’s lightweight title match, which saw both competitors -- Sean Sherk and Hermes Franca -- test positive for PEDs. Both fighters were suspended for one year and fined, though Sherk appealed and had his suspension shortened to six months.Sonnen is staring at a long layoff if he elects not to appeal or is denied. He was scheduled to rematch Silva Feb. 6 in Las Vegas, but that fight may be delayed or scrapped in light of these allegations.Text messages to Sonnen went unreturned.His manager Matt Lindland told Sherdog.com that he was cornering a fighter on the East Coast and had no knowledge of the positive test results.Silva’s manager Ed Soares, who engaged in some heated exchanges via the media in the build up to the fight, was stunned when asked for his reaction.“If it’s true, I feel really bad for him,” said Soares. “I know he did it to himself but it is really sad, he put on such a great performance that night. It is just a shame it will be tarnished.”