ROME, Italy - Serena Williams was forced to withdraw from the Internazionali BNL d’Italia ahead of her second-round clash with sister Venus Williams citing a continuing left knee injury, the tournament announced today.

As a result, Venus advanced into the third round via walkover.

“I must withdraw from the Italian Open due to pain in my left knee,” Serena announced. “I will miss the fans and competition at one of my favorite tournaments.

“I’ll be concentrating on rehab and look forward to seeing you all at the French Open and next year in Rome.”

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Serena is a four-time champion in the Italian capital, and she owns more match wins here than any other active player, an impressive 43-8 record.

She started her 2019 Rome campaign with a solid straight sets win against qualifier Rebecca Peterson, easing through to a 6-4, 6-2 victory to book the highly-anticipated clash against Venus.

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But the former World No.1 has struggled with her injury earlier in the season, being also forced to withdraw from the Miami Open after the second round with a left knee injury.

Serena’s next tournament is scheduled to be Roland Garros, which begins on May 26.