Serena Williams pulls out of U.S. Open

Serena Williams poses for photographers as she holds the winners trophy after defeating Russia's Vera Zvonareva (L) in the womens' singles final at the 2010 Wimbledon tennis championships in London, July 3, 2010. REUTERS/Toby Melville

NEW YORK (Reuters) - American world number one Serena Williams has pulled out of the U.S. Open because she is still recovering from surgery on her right foot.

Williams, who won her 13th grand slam at Wimbledon earlier this year, cut her foot on broken glass at a restaurant in July and has not played since.

"It is with much frustration and deep sadness that I am having to pull out of the U.S. Open," Williams said on the tournament's website ( "My doctors have advised against my playing so that my foot can heal."

The U.S. Open begins August 30 at Flushing Meadows.

Reporting by Simon Evans in Mason, Ohio; Editing by Frank Pingue