The top eight players qualify for the US$3-million event, and Williams opted out despite sitting seventh in the standings. The Wimbledon champion said she hasn't recovered after experiencing dizzy spells at the U.S. Open.
"The accumulation of matches has taken its toll and I have received several medical opinions to delay my return to competitive tennis," Williams said in a statement Sunday. "I look forward to playing in the New Year for what will hopefully be an even better 2008."

Sharapova won her debut at the 2004 WTA Championships and has qualified every year since. [source canadianpress ]
See this sexy photograph of Maria sharapova sexy pose.
