Story highlights Petra Kvitova robbed in city of Prostějov

Suffers left hand injury during robbery

Undergoes surgery for nearly four hours

Will wear cast for six to eight weeks

(CNN) Two-time Wimbledon champion Petra Kvitova says she is "shaken, but fortunate to be alive" after being severely injured by a knife-wielding robber in her apartment Tuesday.

The Czech tennis star suffered damage to the tendons and nerves of her left, playing hand and underwent nearly four hours of surgery.

"I was attacked in my apartment by an individual with a knife. In my attempt to defend myself, I was badly injured on my left hand," she said on her Facebook page before her lengthy operation.

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"I am shaken, but fortunate to be alive. The injury is severe and I will need to see specialists, but if you know anything about me I am strong and I will fight this."

Czech police told CNN that the attack took place just before 8.30 a.m. CET in Kvitova's apartment near the center of Prostejov, a small city about 160 miles east of Prague where a number of Czech tennis pros live and train during the offseason.

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