Hingis voices doubts over 2012 Olympics

Former world No 1 Martina Hingis expressed doubts on Monday on any surprise participation at the 2012 London Olympics, the five-time Grand Slam winner content with her life after tennis.

The 30-year-old played a pro-am on opening day at the San Diego Open, then all but ruled out a return, even if the invitation to play mixed doubles at the Games came from the camp of countryman Roger Federer.

"I'm not really thinking about it at all," Hingis said. "The invitation has been blown a bit out of proportion. I may be retired but the competitive instinct is still there.