NEW YORK -- Serena Williams could miss the French Open and Wimbledon while she takes several months off to recover from a chronic left knee injury.

"What I can tell you today, based on what I am being told by my doctors, is that I should be in a position to be playing again by the end of this summer," Williams said in a statement released Wednesday by her publicist.

The French Open starts May 29, and Wimbledon begins June 26. The year's final Grand Slam tournament, the U.S. Open, starts Aug. 28.

Williams, 24, has played in just four matches over the last 7 1/2 months. Her only tournament this year was the Australian Open, where she lost in the third round.

Once ranked No. 1 and the winner of seven Grand Slam titles, Williams is now 106th in the WTA Tour rankings.

"I know that there has been a lot of public speculation about me and my playing career," Williams said. "I want everyone, and in particular all of my fans who have meant so much to me throughout my career, to know that I will be back on the tennis court and that I fully intend to be competing on the Sony Ericsson WTA Tour in the coming months."