Top-ranked Serena Williams 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 and is ranked No. 1 in the world, 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 Web site. "My doctors have advised against my playing so that my foot can heal." She called missing the tournament "one of the most devastating moments of my career."

The tournament starts Aug. 30.

•Andy Roddick and Mardy Fish will meet in an All-American semifinal at the Cincinnati Open after knocking out Novak Djokovic and Andy Murray, respectively in Friday's quarters. Roger Federer also advanced to the semifinals but top-ranked Rafael Nadal lost to Marcos Baghdatis. … Svetlana Kuznetsova and Vera Zvonareva reached the semifinals in Montreal.