Zurich surgeon Heinz Buehlmann operated on Hingis's ankle in May last year but said in an interview with Sonntags Blick newspaper that the problem had healed perfectly.

Buehlmann added that providing Hingis, who last week said she feared she could be forced to retire, could train through an initial pain barrier the 22-year-old would return to the world stage.

"Martina can play again," said Buehlmann, who said the five-time Grand Slam winner is suffering from inflammation of her left foot.

"Martina has had this problem for four years, but the joints of Martina's foot which was operated on is absolutely okay.

"From a medical point of view a comeback would be no problem, but Martina would have to grit her teeth. She would have to be prepared for some pain.

"I know Martina very well. I know from the past that she can come back. But whether she wants that, I do not know."

PREMATURE END Hingis, who is studying for a degree in English, enjoyed a weekend skiing trip to St. Moritz where she tried bobsledding for the first time, and said she is happy away from the court.

But she told the newspaper that a comeback has not been ruled out despite announcing last week that the problem could bring a premature end to her glittering career.

"I feel relieved," she said of making the announcement about her future. "The pressure and the stress (of the situation) has now gone.

"It is as if a completely new period of life has begun.

"But I do not want to completely exclude a return. It is possible if I can play completely pain-free tennis again, but that is not the case with my foot injury yet.

"I do not have a comeback plan though. I am leaving everything in the future open."