Martina Hingis can't help but contemplate yet another comeback when she sees the success Kim Clijsters and Justine Henin are having after being away from tennis.
"There's a spark," Hingis said in a telephone interview with The Associated Press.
But she also said she would rule out the possibility of a return to the tour "at this point," primarily because of all the travel.
"If it was played in the backyard," Hingis said from her home in Switzerland, "then I'd probably think about it twice."
The five-time Grand Slam singles champion and youngest woman to be ranked No. 1 retired for the second time in 2007, when she was given a two-year suspension for testing positive for cocaine.
That ban ended Sept. 30, and the 29-year-old Hingis is eager to get the chance to play more tennis this year: She has committed to a full season of World TeamTennis, the coed league founded by Billie Jean King and heading into its 35th season.
Hingis will be picked by a team in the marquee player draft Feb. 11. Other top names in the draft include the Williams sisters, John McEnroe and Maria Sharapova, although they're going to be playing only one to five matches, while Hingis is slated for all 14 in the regular season.
In 2005, Hingis used World TeamTennis to help prepare for her first comeback. Clijsters also played in the WTT last year as a way to warm up before getting back on tour after more than two years away.
For Clijsters, that return was as successful as could be: She won the championship at the 2009 U.S. Open, the very first Grand Slam tournament -- and only third event overall -- of her return. That helped prompt another Belgian, Henin, to come back, too, and she managed to reach last weekend's Australian Open final at her first Grand Slam in two years.
"It's great to see them dig deep and come back that well. I don't know if I could handle it," Hingis said.
She watched more of this Australian Open than she has in years.
"What I miss is probably ... the winning moments -- when you hold up the trophy and you know you are the best in the world and you end up winning Grand Slams. That is probably the moment an athlete is most happy," Hingis said.
"You miss that, but you know that getting to that point takes a lot of years, a lot of hard work, a lot of practice. It doesn't come from heaven," she added. "You never forget how much work, how much pain, you go through to get there."