VARESE, Italy — Lance Armstrong might not be able to start his comeback in January in Australia because of the doping rules that apply to riders coming out of retirement.

Elite riders need to be in the sport's anti-doping program for six months before they can race, cycling's governing body said Saturday. The UCI will discuss with the U.S. Anti-Doping Agency whether the seven-time Tour de France winner has met that requirement. The UCI said it will decide next week if Armstrong can race in the Tour Down Under set for Jan. 20-25.

On Sept. 8, USADA confirmed to the Associated Press that Armstrong was part of its out-of-competition testing pool and said he would be eligible for elite competition on Feb. 1, 2009.

UCI president Pat McQuaid said Saturday "the rules must be respected."

Rule 77 of the International Cycling Union's anti-doping program outlines when riders can begin their comeback in official races.

"A rider who has given notice of retirement from cycling to the UCI may not resume competing at international level unless he notifies the UCI at least 6 months in advance before he expects to return to international competition and is available for unannounced out of competition testing at any time during the period before actual return to competition," the rule says.

Armstrong has run marathons and competed in small races since retiring.

"We have to look into that," McQuaid said. "I am not sure what the exact dates are that he started the program."

The issue is the official day of return that has been recorded in the anti-doping books.

On Aug. 9, Armstrong finished second in the Leadville-100 "Race Across the Sky," a lung-searing 100-mile mountain bike race through the Rockies.

Astana spokesman Philippe Maertens said Armstrong had registered with USADA before that, but could not specify further.

Armstrong officially announced on Sept. 9 that he was returning to cycling after three years in retirement in a bid to win the Tour de France for an eighth time. That date was less than five months before the start of the Tour Down Under.

Armstrong has joined the Astana team directed by his former manager, Johan Bruyneel, and made drug testing a cornerstone of his comeback. He had been hounded by doping suspicions during the time he dominated the Tour.