The reigning Wimbledon champion announced her withdrawal before she was due to take the court for her third-round match against Spain's Sara Sorribes Tormo
He is a young player who has incredible skill and determination to be one of the best players in the world. It would be unfair to compare him to Sachin and Virat so early in his journey, said Kirsten
Nadal is just 1-3 this season and has dropped seven of his past nine matches overall, dating to a fourth-round loss to Frances Tiafoe in the US Open's fourth round last September