Sept 9 (Reuters) - Former world number one Kim Clijsters has taken a wild card for the Chicago Fall Tennis Classic next month, the Belgian said on Thursday, as she prepares for her first competitive appearance on the women"s tour since last year"s U.S. Open. The WTA 500 hardcourt event is scheduled to be held from Sept. 27 to Oct. 3. "Thanks for the wildcard @ChiTennisFest," Clijsters tweeted. "Looking forward to visiting Chicago for the first time and getting back on tour again." The 38-year-old pulled out of the WTA 1000 event in Miami earlier this year saying she was not yet ready to compete at her best after having knee surgery in October 2020 and contracting COVID-19 in January. read more The mother of three had come out of retirement for a second time in February 2020, and her last match was an opening round defeat by Russia"s Ekaterina Alexandrova at Flushing Meadows a year ago. Clijsters won the U.S. Open in 2005 before her first retirement two years later. She returned to the sport in 2009 and won a second major title in New York as an unseeded wild card in her third tournament back. The Belgian defended her U.S. Open crown in 2010 and picked up the last of her four major titles at the Australian Open in 2011 before retiring again in 2012.