Petra Kvitova has hamstring injury

EASTBOURNE, England -- Former Wimbledon champion Petra Kvitova has withdrawn from the Aegon International with a hamstring injury, giving British wild-card entry Heather Watson a walkover into the semifinals of the grass-court tournament.

The second-seeded Czech, who won the Wimbledon title in 2011, felt the injury to her right hamstring following her first-round win over Lucie Safarova but still managed to play her second-round match against Varvara Lepchenko.

Kvitova says she is uncertain of the full extent of the injury but will get treatment and expects to play at Wimbledon next week.

She says, "I hope that just some days off will help."