Kim Clijsters is set to play her first match since 2020 at the Chicago Fall Classic on Monday. The former No.1 announced in 2019 that she would be coming out of retirement in 2020, and after the pandemic stalled her momentum, the 38-year-old Belgian will face Hsieh Su-Wei in just her fourth match since retiring at the 2012 US Open.

READ: Clijsters announces 2020 comeback - 'I love the challenge'

"I've been practicing for a long time so I'm excited to start playing matches again," Clijsters told reporters during her pre-tournament press conference in Chicago. "That's the reason I'm here, to play more matches so I can slowly build my level and get more match rhythm and match routine under my belt. 

"I feel like in practice I'm doing a lot of things well and I'm getting fitting and stronger. Now it's just a matter of trying to get enough matches."

The four-time major champion has described her decision to return to the tour as "her marathon". While her friends are training to run marathons before they turn 40, Clijsters is pounding the pavement on tour.

"To see him go through the things he's gone through and be open about the challenges of it and the belief that he has, I feel like it's something I can relate to."

Prior to the pandemic, Clijsters kicked off her most recent comeback at the 2020 Dubai Duty Free Tennis Championships, where she drew Australian Open finalist Garbiñe Muguruza and lost 6-2, 7-6(6). After bowing out in the first round of Monterrey to Johanna Konta before the pandemic shut down the sport for four months, and returned at the US Open that fall. In New York, Clijsters won the first set of her comeback before losing to Ekaterina Alexandrova 3-6, 7-5, 6-1. 

"Going to some of the events and hitting with some of the players just triggered a challenge within myself," Clijsters said. "That was the main reason, that little trigger of, I wonder if I can get myself in a situation where I can play the tennis I like to play and I know I can play."

Post-retirement success is well-tread territory for the affable Belgian, who retired for the first time in 2007 at the age of 23. When she returned to the tour unranked two years later after the birth of her daughter Jada, Clijsters proceeded to win the US Open in just her third tournament back. She went on to win two more majors at the 2010 US Open and 2011 Australian Open, the 2010 WTA Finals in Doha, and rose to No.1 in 2011 before retiring a year later. 

"With me and my stage now, a lot of things are new. Understanding how my body reacts differently after three children. I feel like I've been able to play more practice sessions in a row than I have in a long time. So that feels really good, being able to do that."

"I try to do all my workouts either really early - I'm a 5 a.m. person - doing a workout before the kids wake up, and trying to get everything done when the kids are in school. "Then I can do all the normal things that parents do: driving them to their hobbies, cooking and cleaning. I love the challenge." 

Clijsters says she has no concrete goals as she ramps up her comeback. She was a player who relied on gut instinct and feel during her career and that has not changed. So long as she is motivated and seeing improvements, Clijsters says motivation will not be an issue.

"Seeing Andy Murray and the way he speaks about his comeback and everything, it's so motivating and it gives you a lot of energy too," Clijsters said. "To see him go through the things he's gone through and be open about the challenges of it and the belief that he has, I feel like it's something I can relate to."

2020 Dubai Highlights: Muguruza triumphs in Clijsters comeback match