(AP) - Venus Williams is done for the season because of a left knee injury that has sidelined her for most of the second half of 2010.
In a statement released to The Associated Press on Wednesday, the seven-time Grand Slam champion said she is "very disappointed to announce that I will be unable to play" in the WTA Tour Championships at the end of October and the Fed Cup final between the United States and Italy at San Diego in November.
"I have been getting treatment and therapy on my knee and have been making progress but unfortunately must continue to keep weight off my knee for the short term and won't be ready to return to competition in 2010," Williams said. "I am looking forward to returning to full health in time for the start of 2011 season and hopefully having the opportunity to play in both the Fed Cup and WTA Championships next year."
She is No. 3 in this week's WTA rankings and went 38-7 with two titles in singles and 18-1 with three titles in doubles this season, earning more than $2.5 million in prize money.
But Williams hasn't played anywhere since losing in three sets to eventual champion Kim Clijsters in the U.S. Open semifinals on Sept. 10. That will turn out to have been the 30-year-old American's only tournament appearance over the final six months of the year.
After being upset in the Wimbledon quarterfinals on June 29 by a woman ranked 82nd, Williams was out of action until playing in the first round of the U.S. Open on Aug. 30. That's because Williams sprained her left kneecap shortly before she was supposed to enter a hard-court tournament at Cincinnati in early August. The injury kept her out of another U.S. Open tuneup at Montreal that month, too.
It was an up-and-down season for Williams, who has been using crutches to keep weight off her left leg.
She was one of two women who reached at least the fourth round at all four Grand Slam tournaments in 2010 -- but she made it past the quarterfinals only at the U.S. Open.
Her singles titles both came in February -- at Dubai on hard courts and at Acapulco on clay. Her doubles titles, all while paired with younger sister Serena, came at the Australian Open, French Open and Madrid.
In August, Venus and Serena -- who has been sidelined since having surgery on her right foot in July -- both told the U.S. Tennis Association they planned to play against Italy in the Nov. 6-7 Fed Cup final on an indoor hard court at the San Diego Sports Arena.
"I spoke to Carlos [Fleming, Venus' agent] today and learned that Venus is done for the rest of the season with a left knee injury. It's unfortunate that Venus is hurt again and won't be able to play in the Fed Cup final," U.S. Fed Cup captain Mary Joe Fernandez said Wednesday. "We wish her a speedy recovery so that she is ready for next year."
Neither Williams has competed for the U.S. Fed Cup team since 2007. Venus owns a 17-4 career record in Fed Cup action, including 14-2 in singles. She last participated in the 2007 semifinals.
The USTA still expects Serena to be on the team for the matches against Italy.
The rest of the U.S. roster includes 2009 U.S. Open quarterfinalist Melanie Oudin, Bethanie Mattek-Sands and leading doubles player Liezel Huber.
The United States hasn't won a Fed Cup title since 2000 and lost to Italy in last year's final.