Venus Williams pulled out of the French Open on Friday, 24 hours after her younger sister Serena withdrew, making it the first Grand Slam tournament since 2003 without either Williams.
Venus' agent, Carlos Fleming, wrote in an e-mail to The Associated Press that the seven-time Grand Slam champion notified tournament organizers she wouldn't compete at Roland Garros, where play starts May 22.
The 30-year-old American has been off the tour since January, when she stopped playing only minutes into a match in the third round of the Australian Open because of a hip injury. A left knee injury limited her to just one tournament over the final six months of 2010.
Serena pulled out of the French Open on Thursday; she hasn't entered a tournament since winning her fourth Wimbledon singles championship in early July. A few days later, she cut her foot on glass at a restaurant in Germany, an injury that led to two operations. The second surgery was in October, and she said she spent 10 weeks in a cast and 10 weeks in a walking boot.
She returned to practice last month and said Thursday in a statement issued by her agent that she hopes to "be back competing this summer."
The sisters are among the most dynamic and attention-drawing players in tennis history. Both were ranked No. 1 by the WTA, and they own a combined 20 Grand Slam singles titles - 13 for Serena, seven for Venus. They have played each other in eight major finals, including at the 2002 French Open, won by Serena.
But a series of health problems have limited them lately, and in this week's rankings, Serena is 17th, Venus 19th.
While the 29-year-old Serena hasn't pointed to a specific target date for her return to action, Venus is entered in a grass-court tournament in Eastbourne, England, that begins June 11. Fleming wrote Friday that Venus "is on track to be ready to play at Wimbledon," which starts June 20.
This French Open will be the third consecutive Grand Slam tournament missed by Serena. Venus, though, had played in the previous 16 in a row, and 30 of the last 32.
The only other time both Williams sisters pulled out of one of tennis' four major tournaments was the 2003 U.S. Open, when Venus had an abdominal injury, and Serena was coming off left knee surgery. Before that, one or the other - and usually both - participated in every Grand Slam tournament since Serena's first, the 1998 Australian Open.