Garbiñe Muguruza pulled out of the Madrid Open on Thursday after failing to recover from a leg injury.
The Spaniard was scheduled to face Sloane Stephens in the first round.
“This is the worst news and the most painful decision any player can make,” Muguruza said. “But the problem has come back and the last scan confirmed that I’m not 100% recovered to be able to compete and the medical recommendation is to rest.”
Also, Jil Teichmann beat fourth-seeded Elina Svitolina 2-6, 6-4, 7-6 (5) in the first round, while Angelique Kerber defeated Marketa Vondrousova 7-6 (5), 6-1 and Kiki Bertens beat Victoria Jiménez 6-4, 6-0.