Recent top-10 player Andrea Petkovic of Germany has withdrawn from Wimbledon because of a persistent right ankle injury.
She missed the Australian Open because of a lower back injury, then hurt her ankle in her comeback tournament and has missed the French Open.
Petkovic reached three Grand Slam quarterfinals last year at the Australian, French and U.S. Opens, and the third round at Wimbledon.
She was replaced by Bojana Jovanovski of Serbia.
Hungary's Agnes Szavay (back) and Estonia's Kaia Kanepi (foot) also withdrew, and replaced by Lesia Tsurenko of Ukraine, and Britain's Heather Watson of Britain.
Pablo Cuevas of Uruguay, who has hardly played in more than a year, was replaced by Vasek Pospisil of Canada, who will make his Wimbledon main draw debut.