ROME (AP) – Serena Williams retired from the Italian Open Tuesday ahead of his second round match against Sister Venus due to a previously injured left knee.
The tournament organizers announced one day after Serena opened his clay high season with a straight-set win over Swedish qualifier Rebecca Peterson.
"I have to withdraw from the Italian Open because of pain in my left knee," said Serena, according to the WTA website. "I will miss fans and competition at one of my favorite tournaments. I will concentrate on rehab and look forward to seeing you all in French open and next year in Rome."
Next tournament on Serena's schedule is Roland Garros, which starts in less than two weeks.
It is the third straight event that the 37-year-old Serena has left due to physical problems.
She retired because of a viral disease in her third round match against Garbine Muguruza in Indian Wells, California; and retired with left knee injury before her third round match at the Miami Open in March.
As a result of this latest retreat, Venus enters the third round via a walkover.
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