"We're going to play doubles. I'm pretty excited about it.
"It doesn't happen every day that such an amazing athlete, not only in tennis but overall in sports, asks you to play tennis with her. I hope it's going to be fun," Muchova told a press conference in Berlin on Saturday.
Williams, a 23-time Grand Slam singles champion, had retired after the 2022 US Open.
On Tuesday, the 44-year-old won her first doubles match at the Queen's Club in London alongside Canadian Victoria Mboko.
Mboko then injured her left knee, forcing her to retire from the singles and the doubles.
The 29-year-old Muchova, ranked 10th in the world, was runner-up at the 2023 French Open singles tournament.
The Berlin Open serves as a warm-up for Wimbledon from July 1st to 14th.
