The United States Anti-doping Agency says it's up to cycling's international governing body the UCI to decide when Lance Armstrong will be eligible for competitive racing.
Armstrong remains hopeful of returning to professional cycling in Australia's Tour Down Under in January despite being ineligible for the race.
The seven-time Tour de France winner hasn't registered for doping tests in time to compete in the annual Adelaide event.
Under UCI rules, a cyclist coming out of retirement must register for testing six months before resuming international competition with Armstrong's six-month probation period only officially beginning in August.
