DENVER - Daniel Stumpf said fish oil is the only supplement he has ever taken and he has no idea how he tested positive for an anabolic steroid.

The relief pitcher returned to the Phillies on Sunday morning at Coors Field at the completion of his 80-game suspension for testing positive for chlorodehydromethyltestosterone, a discontinued steroid that was used by East German athletes under the brand name "Oral Turinabol."

"I understand that it's going to be hard to believe for people. I understand that people say all the time that they don't know how it got into their system," Stumpf said. "I know that there's been chatter out there from people saying, 'If you're taking an uncertified supplement then you're taking the risk of that.' Well, I don't take supplements period. I don't drink protein. I don't do pre-workout. I don't eat protein bars. I don't go to Smoothie King and drink smoothies, strictly because they mix stuff in their smoothies."

Stumpf's positive test occurred during spring training. The Phillies acquired him last December in the Rule 5 draft. He had never pitched above double A, but a strong spring would ensure a major-league contract worth more than $500,000. Stumpf said he lost 12 pounds during camp from an illness and his fastball was sapped of velocity.

"I was losing everything in spring training and apparently I'm taking a performance enhancing drug," Stumpf said.

Stumpf was suspended after pitching in three games and he allowed three runs in his major-league debut without recording an out. Stumpf is one of five baseball players - including Phillies minor-league pitcher Alec Asher - to be suspended this season for Oral Turinabol. None of them have an explanation. Frank Mir, a former UFC heavyweight champion, tested positive for it in May. The players have spoken to Mir, who said his positive test may be caused by kangaroo meat he ate in Australia.

"It doesn't make sense to me," Stumpf said. "My only thing on that is that drug testing should be black and white. There's a lot of gray areas here. There's a lot of questions that can't be answered."

Stumpf did not appeal his suspension, because the union told him he had no chance to win. Stumpf said they examined close to 60 medications, including cough drops, lotions, and ChapStick. None of them came back contaminated. The appeal, he said, would only prolong his suspension.

"I specifically told the union when I was going through this, I don't care if I have proof or not, I want to sit down in front of these people and I want them to tell me that I'm a liar, that I did this," Stumpf said. "I'm going to argue to you that I did not. And so they said that's not enough. That my word isn't good enough to them . . . .I told them if I didn't appeal I'm not admitting guiltiness. So yeah, I then sat down with the general manager, I sat down with the manager, and then I sat down in front of my teammates and I cried my eyes out telling them the issue that I was having to go through. I mean, I had nothing to hide. I still don't have anything to hide."

To make room for Stumpf, the Phillies sent relief pitcher Severino Gonzalez to triple A and designated lefthanded reliever Mario Hollands for assignment, removing the pitcher from the 40-man roster. Stumpf is the first Phillies player to test positive for performance-enhancing drugs, serve his suspension, and return to the team in the same season.

"My teammates believe me. The Phillies believe me. God knows what I did. I don't have to prove myself to anybody," Stumpf said. "Obviously there's a bunch of guys in the game right now that are running their mouths now about this. And that's fine. But again if this can happen to me it can happen to you. So I'm not nervous about meeting any of the guys. I've talked to a bunch of them in there right now. They're welcoming me back with open arms. I'm ready to go. I'm ready to step between those white lines again."

Extra bases

The order of the Phillies pitching rotation for the second half will be: Jeremy Hellickson, Jerad Eickhoff, Zach Eflin, Aaron Nola, and Vince Velasquez.