Williams, 28, sliced her right foot on a piece of broken glass at a restaurant in Munich last month, a few days after winning her fourth Wimbledon singles title. She had surgery in mid-July and has not played since. At last year’s Open, Williams lost to the eventual champion Kim Clijsters in the semifinals, a match remembered mostly for her climatic tirade against a line judge who called a foot fault.

“It is with much frustration and deep sadness that I am having to pull out of the U.S. Open,” Williams said in a statement released by her publicist. “My doctors have advised against my playing so that my foot can heal.”

Andy Roddick, the 2003 Open men’s champion, was surprised that Williams, the winner of 13 Grand Slam singles titles, withdrew more than a week before the tournament. “The U.S. Open is probably her favorite event, so if she’s this far out and is not going to play, it’s got to be something pretty serious,” Roddick said at a men’s tournament in Mason, Ohio.

The absence of Williams, a fan favorite on and off the court in New York who is frequently scheduled to play in prime time, will open the tournament to a broader group of contenders. “We regret that Serena Williams is unable to play the U.S. Open and wish her a speedy recovery,” the tournament director, Jim Curley, said in a statement.

The lasting image from last year may be Williams’s verbal assault of a line judge near the end of her taut match with Clijsters. Serving late in the match, Williams was called for a foot fault. Angered, she turned and stepped toward the female judge, held up a ball and, with profanity, said she would shove it down her throat. The episode cost Williams a code violation on what would have been match point, so the match ended without another ball put in play. Clijsters won, 6-4, 7-5, then beat Caroline Wozniacki in the final.

In late November, Williams was fined a record $82,500 by the Grand Slam committee and warned that she would be suspended from the tournament if she had other major offenses at a Grand Slam event in 2010 or 2011. She eventually apologized for her “inappropriate outburst” on her Web site and Twitter page. There were no online pronouncements from Williams until late Friday.

“I’m devastated to not be participating” in the Open, she wrote. “Grand slams are my life. My soul. ... I will miss it more than u can ever imagine.”