Tokyo, Japan (Sports Network) - World No. 1 superstar Serena Williams has withdrawn from next week's Pan Pacific Open in Tokyo, citing fatigue.
Williams is a two-time champion at the Pan Pacific event, capturing both of her appearances there in 2001 and 2002.
The 31-year-old American has played in Asia only once since 2005.
"I'm disappointed to have to withdraw from the Pan Pacific Open, which I was very much looking forward to playing this year," Williams said. "Unfortunately, with the number of matches I have played throughout the summer, I need more time to properly recover."
Williams captured her fifth U.S. Open title two weeks ago and is a brilliant 67-4 overall this season, including a French Open title as well.