COLORADO SPRINGS, Colo. — Gymnast Morgan Hamm, who was selected for his third Olympic team last month, received a warning today for getting a prescribed anti-inflammatory shot without the proper clearance from anti-doping authorities.

The U.S. Anti-Doping Agency said Hamm tested positive May 24 at the U.S. gymnastics championships for a glucocorticosteroid, a cortisone-like drug that is only allowed during competitions with an exemption. Hamm said he received the shot May 2 for pain and inflammation in his left ankle, which he initially injured last August.

"It was an innocent mistake," Hamm said. "You always need to get the forms, that's the most important thing, and that's my failure."

Hamm accepted the warning for his first doping violation, and his results from the May 24 competition at nationals were thrown out. Results from that day, as well as the first day of nationals and two days of Olympic trials, were used to help determine the U.S. team for Beijing.

Calls to USA Gymnastics president Steve Penny and Ron Brant, men's national team coordinator, were not immediately returned.

"Morgan is good enough and has earned a position on the Olympic team," said Hamm's coach, Miles Avery. "If not for forgetting to fill out a form, we wouldn't even be talking about this today."

Hamm had the second-highest score on high bar after four days of competition at nationals and trials, and tied for fourth on floor, pommel horse and vault.

"So long as the proper documentation is provided to USADA, this will not be a problem going forward," U.S. Olympic Committee spokesman Darryl Seibel said.

The anti-inflammatory Hamm took is on the World Anti-Doping Agency's list of prohibited substances, but athletes can take it before a competition if there is a medical need for it and if they receive an exemption. Hamm said he was given the drug by his doctor, Mark Triffon, after taping, ultrasound and other therapies didn't reduce the pain and swelling in his ankle, but failed to ask for the therapeutic use exemption.

Hamm said he didn't realize he needed the exemption. Avery said he was aware an exemption was needed but failed to remind Hamm.

"I should have reminded him and made sure, 'Let's get this TUE form to be on the safe side with that,"' Avery said.

Hamm took full blame for the error and called the warning, the least of USADA's punishments, "a fair decision."

"It's a mistake I shouldn't have made," he said. "I'm paying for that mistake."

Hamm was notified of the doping violation a few days after he returned from the Olympic trials in Philadelphia, where he and twin brother Paul were named to the U.S. squad for the Beijing Games.

"At first it was just shock. I couldn't even think of anything I had done that would result in a positive test," said Hamm, who added Advil is the only anti-inflammatory he normally takes.

When Hamm realized it was the shot that had caused the positive, he sent USADA his medical records, as well as letters from his doctor and physical therapist.

"We have absolutely no concern it was intended to enhance performance," said Bill Bock, USADA's general counsel. "We are absolutely confident it was an anti-inflammatory, taken for a legitimate medical purpose."