Kim Clijsters: Former world number one to return to tennis aged 36
Kim Clijsters is to make her tennis comeback at the age of 36 with a return to the WTA Tour in 2020.
The Belgian, who first retired in 2007 to start a family, says she has been "inspired" by other mothers such as Serena Williams and Victoria Azarenka.
The ex-world number one returned in 2009 and won three more Grand Slams before her second retirement in 2012.
"Mothers are trying to compete at the highest level - that is the inspiration," she said.
"I don't really feel like I want to prove something. I think for me it's the challenge.
"My goal right now is to be able to be fit enough to compete at the highest level and then if you get to that stage, let's see if I can get to the second stage of a Grand Slam.
"I will continue to push myself each goal I set."
Clijsters is targeting a return in January, but says she will remain flexible in her scheduling.
As a former world number one, Clijsters is eligible for unlimited wildcards at WTA tournaments. She will need to play three tournaments or earn 10 ranking points to re-establish a ranking.
She said not having to play a set number of tournaments a year has "made the choice a little bit easier".
"Kim Clijsters ranks among the greats of the game and her return to the Tour is exciting news for the WTA family and tennis fans around the world," said WTA chairman Steve Simon.
Clijsters won 41 WTA titles and spent 20 weeks as world number one in her two previous spells.
Her daughter Jada was born in 2008, followed by sons Jack in 2013 and Blake in 2016.
Whilst training for her comeback, she has been working out with her daughter, who plays basketball.
She said: "She is excited for it. She motivates me.
"She plays basketball so we often train together and push each other and it's great to be an example of what you have to do and not do to be an athlete and get the best out of yourself."
Following her second retirement Clijsters ran her tennis academy and worked as a commentator, including for the BBC at Wimbledon.
She says she has been contemplating a comeback for two years.
"Even if I don't make it, this whole process has been so worth it for me to get back into a good routine," she said.
"Let's see if I can get my body in shape to play tennis at a level where I would like it to be at, that I have in mind of where I would like to get to, and see if it's possible. To see, first of all, if my body is capable of even doing that.
"I know it will not be playing for the whole season - my children are still young and I don't want to be away all the time.
"For my youngest it is not really a big deal, but for my eldest, it's important to not take her away from school, her friends and her basketball team too much. We need to find a balance."
Russell Fuller, BBC tennis correspondent
Winning is still the ultimate goal, Clijsters admits, but she is not setting herself any specific targets just yet.
Success at this stage, she says, would be to get herself at the standard required to compete among the elite once again. She would love to make her comeback in Australia in January, but will only do so if ready.
Clijsters says she won't play anything like a full season.
She does not want to be away from her family for much more than a couple of weeks at a time, so her schedule may be designed with the school holidays in mind - when the children can travel.
It will be fascinating to see how Clijsters gets on. How will the champion, renowned for her versatile game, great return and excellent movement fare against those younger and more powerful players?
BBC Sport has launched #ChangeTheGame this summer to showcase female athletes in a way they never have been before. Through more live women's sport available to watch across the BBC this summer, complemented by our journalism, we are aiming to turn up the volume on women's sport and alter perceptions. Find out more here.