"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 September 30, and the 29-year-old Hingis was eager to get the chance to play more tennis this year: She has committed to a full season of World TeamTennis, the mixed team league founded by Billie Jean King and heading into its 35th season.
Hingis will be picked by a team on 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 while getting married and having a baby.
For Clijsters, that return was as successful as could be: She won the 2009 US 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 tournament 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.
"Of course it makes you think. Tennis was all my life, and the most natural thing is that it makes you think. It would be sad if it didn't make me think, don't you think?" Hingis said.
"Tennis is still my life. Well, part of it," she continued. "But my life is very comfortable, on the other hand. Tennis gave me a lot of things and sometimes you have to put things behind. It's a lot of sacrifice, as well. I wouldn't want to risk it anymore."
She originally quit tennis in 2002 because of foot and leg injuries. When she rejoined the circuit full time in 2006, she reached two Grand Slam quarterfinals, won two smaller tournaments and made it to No. 6 in the rankings.
"It has been a while since I have seen her play, but Martina did ask me a few years ago if I thought she still had what it took to win on the Sony Ericsson WTA Tour today. I think she still knows what it takes to win and is committed to the task at hand," said King, who won 12 Grand Slam singles titles.
"With her talent and a renewed commitment, she could do very well. She may not be as powerful as some players, but she knows how to make the most of any point."
At the height of her powers, Hingis was brilliant at controlling exchanges and working every angle. Nicknamed "The Swiss Miss," she became the youngest major champion of the 20th century when she won the 1997 Australian Open at 16, and later that year she moved up to No. 1 in the rankings. She went on to win Wimbledon and the US Open that season, too, coming within a loss in the French Open final of a calendar-year Grand Slam.
"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."