WATCH: Clijsters reacts to outpouring of support

While training for 2020, Kim Clijsters took a moment to acknowledge all of the support and love she's received since making her comeback announcement last month.

"The response has been incredible. I've gotten so many cards and messages through social media... " she said. "It's been emotional but it's been very motivational as well."

The 36-year-old retired at the 2012 US Open after winning four Grand Slams, reaching No. 1 in the world and picking up a total of 41 WTA titles. She'll return as the mother to three children, joining a big group of families on tour.