Clijsters and Lynch, a forward on the Euphony Bree club, are planning to marry Saturday in Clijsters' hometown of Bree, Belgium, People magazine reported Tuesday.
"If everything goes well, Kim will be a mom and I a grandfather next year," dad Lei Clijsters wrote.
The 24-year-old Clijsters, who won the 2005 U.S. Open, in May announced her retirement from tennis after an injury-riddled career. In 2003 she was the first Belgian to be ranked No. 1 in tennis.