Former heavyweight titleholder Shannon Briggs, who launched a comeback last month after 2½ years out of the ring, tested positive for a banned substance following his first-round knockout of Marcus McGee.
The result of the Dec. 3 fight, which took place in New York City and was televised on Versus, was changed to a no contest. Briggs was also suspended for 90 days by the New York State Athletic Commission, according to Ivaylo Gotzev, Briggs' manager.
Gotzev declined to identify the substance that Briggs tested positive for but told ESPN.com on Saturday night that the test result came about because of medication he takes for asthma, which he has battled for years.
"Shannon is on enough medication to kill a horse because of his asthma," Gotzev said. "All the medications he takes, other people couldn't even get out of bed. But he's out there running and training and fighting. He's not a steroid user or a drug user. He's using medication. We're consulting with his physicians and seeing how we can make the proper adjustments so this doesn't happen again.
"Maybe he needs to stay off certain medications before fights. I don't know. I'm not the doctor. But Shannon is on a number of medications due to his asthma. He had something found by the commission, and we've dealt with that."
Briggs was supposed to fight Friday in Glendale, Calif. The card, headlined by a middleweight title elimination match between Roman Karmazin and Dionisio Miranda, will serve as the season premiere for ESPN2's "Friday Night Fights", although Briggs' bout was not scheduled for television.
Now Briggs is planning to return in March or April, after the suspension is up, Gotzev said.
Gotzev said Briggs is considering his options, which include a possible attempt at a mixed martial arts bout.
"Shannon is a fighter, so whatever comes our way we'll be ready, be it MMA or boxing," Gotzev said. "If it makes sense, why not give MMA a try? I don't think [UFC heavyweight champion] Brock Lesnar gets past Shannon's jab."
Another option, Gotzev said, was a potential fight with heavyweight contender Cristobal Arreola, who is tentatively slated to fight on HBO's "Boxing After Dark" on April 24, although it remains to be seen if HBO would approve Briggs as an opponent.
"I have sat down with [Arreola promoter] Dan Goossen and if he's not lying through his teeth, he's said several times on several occasions that he's looking at Shannon as a possible opponent for Cris."
Briggs blew out McGee (22-17, 11 KOs) in 2 minutes, 1 second, dropping him for the full count with a crippling right hand to the ribs.
It was the first fight for Briggs (48-5-1, 42 KOs), who turned 38 on Dec. 4, since June 2007, when he lost a heavyweight belt via decision in his first defense to Sultan Ibragimov in Atlantic City, N.J. Briggs claimed a title in November 2006 when he knocked out Sergei Liakhovich with one second left in the 12th round.
Dan Rafael covers boxing for ESPN.com.