Kvitova withdraws from WTA Championships

• Petra Kvitova has withdrawn from the WTA Championships because of a viral illness
• Samantha Stosur, the first alternate, will replace her in the field
• Kvitova was named Wednesday to the Czech Fed Cup team which faces Serbia in the final next week

ISTANBUL (AP) — Defending champion Petra Kvitova has withdrawn from the WTA Championships because of a viral illness and will be replaced by Samantha Stosur.

The WTA gave no details of Kvitova's illness on Wednesday.

The Czech player lost her opening match Tuesday, falling 6-3, 6-2 to Agnieszka Radwanska.

The season-ending tournament brings together the eight top-ranked players in the world. Stosur was the first alternate.

As a result of Kvitova's withdrawal, if Maria Sharapova wins her match Wednesday (vs. Radwanska) she will advance to the semifinals. As an alternate, Stosur still has a chance to reach the semifinals but she would need to win both of her round-robin matches (vs. Sharapova and Sara Errani).

Also announced Wednesday: Kvitova was selected to lead defending champion Czech Republic in next week's Fed Cup final against Serbia.

Captain Petr Pala named the strongest possible team, the same one that beat Italy 4-1 in the semifinals.

Kvitova, who won Wimbledon and the WTA Championships last season, has not been in such great form this year and was ranked sixth.

Czech team spokesman Karel Tejkal said Kvitova was flying home for treatment and was expected to recover in time for the final.

"I try my best to be ready for the Fed Cup. It's final at home and I really want to play in front of our crowd, my family and friends, and try to win the Fed Cup title again," Kvitova said. "I will try my best to be ready for the weekend."

Lucie Safarova, ranked 17th, was the second singles player, while the doubles pair will be Andrea Hlavackova and Lucie Hradecka, who reached the U.S. Open and London Olympics finals.

The best-of-five final will be on Nov. 3-4 on an indoor hard-court at Prague's O2 Arena.
The Czechs and Serbia will meet for the first time.

The Czechs beat Russia 3-2 in last year's final in Moscow for their first title since the country split in 1993. The Czechs won five more times as Czechoslovakia.