WIMBLEDON, England (AP) -- Two-time champion Serena Williams withdrew from Wimbledon on Friday because of a chronic knee injury.
She had also withdrawn from the French Open, which starts Sunday. Wimbledon starts June 26.
Williams won Wimbledon in 2002 and 2003, beating her older sister Venus in both finals. She reached the third round last year, while Venus won the title for the third time.
Serena Williams has played just four matches during the last eight months. Her only tournament this year was the Australian Open, where she lost in the third round. Once ranked No. 1 and the winner of seven Grand Slam titles, Williams is now 108th in the WTA Tour rankings.