The former world No. 1 announced Thursday that, at 36 years old, she's coming out of retirement for a second time.
"Could I be a loving mom to my three kids and the best tennis player I can possibly be?"
Notoriously friendly, down-to-earth, and a favorite amongst her peers in the locker room, Clijsters hung up her racquet for good - or so she thought - after the 2012 US Open.
She then called time on her career again in 2012, and went on to have two more children Jack and Blake.
"If I want to be able to compete with these girls, I'm going to have to be the fittest that I ever have been and to be able to move like I did in the past".
I don't feel like I need to prove anything, just want to challenge myself and be strong again, this is my marathon.
"For the past seven years, I've been a full-time mom", Clijsters, who has three children, said in a video posted to Twitter.
But Clijsters, 36, is now aiming to return in 2020, potentially competing again with Serena and Venus Williams - the only active players who can match her tally of Tour honours.
"But I also loved being a professional tennis player".
"Let's come back one more time".
Clijsters - now a mother of three - made her WTA debut at the age of 15 in 1999, and was 29 when she retired.
She said the earliest stages of her comeback bid have been filmed by a documentary crew for the past six months, although she decided for sure to give this a real try only in recent weeks.
The Belgian told the WTA Insider Podcast: "I don't really feel like I want to prove something". Multiple US open champion, Clijsters announced a shock return to Tennis at the age of 36 nearly seven years after calling it quits.
Other notable returns to the sport include Martina Navratilova, who retired in 1994 but returned in 2000. She won the Australian Open in 2011.
Following back-to-back titles in NY in 2009 and 2010, she also added the 2011 Australian Open to her list of honours.
Clijsters has 41 career singles titles and 11 career doubles titles.
I'll be the hitting partner for your practice today.