Greg Rusedski is free to continue playing tennis as he awaits the outcome of the hearing into his positive drugs test.
But he would be unable to play if the verdict went against him and he decided to appeal, and that could rule him out of Britain's Davis Cup tie in Luxembourg in early April.
Rusedski made no comment as he left the offices of the tribunal's presiding judge, Yves Fortier QC, by a side entrance on Monday to avoid waiting reporters in his home city of Montreal.
The British number two, accompanied by his wife Lucy and lawyers Mark Gay and David Pannick, got into a waiting car with blacked out windows and headed straight for the airport following the eight-hour hearing.
The 30-year-old was more forthcoming when he arrived at Heathrow airport yesterday morning and revealed he expects the verdict to be announced before the end of next week.
"I am confident and we'll just have to wait and see," said Rusedski, who also felt the tribunal had been conducted `fairly'.
"We are cautiously optimistic and are hoping for the best. I have no idea when I am going to hear the verdict.
"It's anywhere between three to nine days so all we can do is sit tight at the moment."
Rusedski is currently entered for next week's tournament in Rotterdam - where British number one Tim Henman will be in action - but it remains to be seen whether he will be in the right frame of mind to compete.
If found guilty of taking the banned steroid nandrolone after testing positive at a tournament in Indianapolis last year, Rusedski faces a maximum two-year ban from tennis, which would effectively spell the end of his career.
After the verdict is announced, he would have 21 days to appeal to the Court of Arbitration for Sport in Lausanne, after which he could, like former Australian Open champion Petr Korda in 1998, go all the way to the High Court.
However, while the appeal process is ongoing, he would be ineligible to play both in regular ATP tournaments and the ITF-controlled Davis Cup.
Britain face an away tie in Luxembourg starting on April 9, and Davis Cup captain Jeremy Bates will be desperate to have Rusedski available to partner Henman.
