Dwain Chambers will find out Friday if he can compete at next month's Beijing Olympics.
Chambers, who served a two-year doping ban from 2003-05, is seeking a temporary injunction against the British Olympic Association, which has a bylaw banning doping violators for life from the games.
After Thursday's hearing in London's High Court, Judge Colin Mackay said he would announce his ruling Friday.
Mackay noted during the hearing that the sprinter would know that being caught taking steriods resulted in a life ban from the Olympics.
The sprinter's legal team argued in court that Chambers had expressed regret for his past behavior and deserved a place in Beijing, adding that he would strengthen Britain's 100 meter squad.
The deadline to make the team for Beijing is Sunday, and an appeal from either side against the ruling is possible.
Mackay ruled last Thursday that there is not enough time to hear the full case until after Beijing.
Chamber's barrister said the stakes were high for his client and suggested he could retire from athletics.
"If he doesn't go to Beijing, he'll walk into the sunset," Jonathan Crystal told the court. "If he does go to Beijing, that will be the springboard for further and better opportunities."
Although the judge said nine men had run the 100 meters faster than Chambers this year, Chambers was confident before the case that he will be challenging Usain Bolt, Tyson Gay and Asafa Powell for a medal in the 100 meters.
"I will respect the judge's decision," Chambers said Saturday at the British trials, where he won the 100 in 10 seconds flat. "But I strongly believe that decision will go in our favor then I can go and have some fun in Beijing. I've got a confident mind."
BOA chairman Colin Moynihan defended the BOA's stance Wednesday.
"Anyone who has been following the Chambers case knows cheating in sport, taking drugs to get a competitive advantage, is unacceptable in the Olympic movement," he said. "We are going to significant lengths to defend our eligibility bylaws on that.
"I have spent my lifetime in sport. I don't think those who knowingly take drugs to cheat their colleagues at sport should be competing in the Olympic Games."
The 30-year-old Chambers returned to the track this year after serving a two-year doping ban after testing positive for the steroid THG, the drug at the center of the BALCO scandal, in August 2003.Reuse content