The 31-year-old injured her ankle after a freak fall as she was finishing a post-match press conference on Sunday.
Round 1 of the French Open 2021 began on Sunday (May 30), and Japan's Naomi Osaka started the tournament with an easy win.
Kiki Bertens had claimed the Madrid title at the event's most recent edition in 2019.
The three-time champion Kvitova edges past the German to reach the third round in Madrid.
Top seed Ash Barty enters quarterfinals after a hard-fought win against Shelby Rogers, but Petra Kvitova, Garbine Muguruza are out
Serena Williams is the legend of women’s tennis but there are a lot of players who are rising up the ranks and dominating the sport.