Thursday April 4th, 2013

Andrea Petkovic German Andrea Petkovic, coming off major injury, is ranked No. 139. (Al Bello/Getty Images)

CHARLESTON, S.C. -- Andrea Petkovic was forced to withdraw with a calf injury before her third-round match against Caroline Wozniacki on Thursday at the Family Circle Cup. Wozniacki gets a walkover into the quarterfinals, where she'll play either Julia Goerges or Stefanie Voegele.

"I was really having trouble in Miami after the long match I had against Alja Tomjanovic," Petkovic told a small pool of reporters after her first-round win over Taylor Townsend. "My knee swelled up pretty big because we played three hours so I had to rest for three days and try to get it back to normal. And I've been having troubles with my calf because I was compensating because of the knee. So I was really scared for the past few days but now it's calming down with the clay."

Her body couldn't hold up after two matches in Charleston. Granted a late wild card into the tournament, Petkovic tweeted that given her recent run of injuries, which include a stress fracture in her back, ruptured ligaments in her ankle and a right meniscus tear in her knee, she's had to take precautions to protect her health. Petkovic's next scheduled WTA tournament is Stuttgart on April 22.

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