Free-agent defensive end and former No. 3 overall pick Dion Jordan will serve a 10-game suspension for violating the NFL policy on performance-enhancing drugs.
Jordan, 29, learned Tuesday that an arbitrator had denied his appeal, according to NFL.com.
The former Miami Dolphins (2013-14) and Seattle Seahawks (2017-18) defender tested positive three times in four weeks in December and January for the use of Adderall, a prescription medication he had been approved to take in the past to treat ADHD. His therapeutic use exemption (TUE) had expired, however.
"I made a mistake," Jordan told NFL Media's Tom Pelissero by phone on Tuesday.
Jordan told Pelissero he knew his TUE was expired but took the medication to alleviate a stressful time with his family.
"I thought it was going to help me dial in -- for the moment, for the day, whatever," he said. "That was my intentions behind what I was doing. It was a bit much at the time. I'm not saying that it was the right thing. But for myself, it was just what I went to."
Jordan previously served a four-game suspension in 2014 for a PED violation. He was then suspended for the entire 2015 season following another positive test for substance abuse.
Jordan has appeared in 43 games with just four starts, tallying 86 tackles and 8.5 sacks.
He told Pelissero he is staying sober and staying in shape in San Francisco, hoping for another shot in the league.
"I know I have the physical ability to go play football and help somebody win football games," Jordan said.