*The left knee of Venus Williams has ended her 2010 season.

In a statement released to The Associated Press today, 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.”

Venus 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.