Serena Williams of the United States smashes a backhand to Flavia Pennetta of Italy during their evening match at the U.S. Open tennis championship in New York, September 8, 2009. Serena Williams beats Flavia Pennetta of Italy 6-4, 6-3 during the quarterfinals of the U.S. Open tennis tournament in New York, Tuesday, Sept. 8, 2009.(Xinhua/Reuters Photo) Photo Gallery>>>

    TOKYO, Sept. 25 (Xinhua) -- World No. 2 Serena Williams has announced to skip next week's Pan Pacific Open due to her knee and toe injuries, said the organizers on Thursday.

    Serena, who rant at a lineswoman in her semifinal loss to comeback Belgian Kim Clijsters at the U.S. Open women's singles final earlier this month, has not played competitive match since the last Grand Slam event.

    The Australian Open and Wimbledon champion was initially named in the two million event alongside with the rest of the women's world top 10 including her elder sister Venus.

    World No. 1 Dinara Safina, who was not on the initial entry list, has opted to compete in Tokyo in a bid to retain the Pan Pacific crown she won last year.