WASHINGTON, May 3 (Xinhua) -- Serena Williams, former world number one of the United States and a seven-time Grand Slam champion, will miss Wimbledon and the French Open this year because of a chronic left knee injury, it was reported from St. Petersburg, Florida Wednesday.

    Williams, only 2-1 this season, reached the third round of the Australian Open in a title defense in her only appearance so far this year.

    "These past few months have been very frustrating for me personally, as I have had to take this time off to fully mend from a chronic knee injury," Williams was quoted as saying.

    That could put her in position to play in the US Open, where she won her first major title in 1999.

    The 24-year-old took nine months off in July of 2003 after winning Wimbledon. She returned in March of 2004 and won a tournament in Miami.

    Williams won four Grand Slam titles in a row starting at the 2002 French Open and also took Wimbledon in 2003 as well as the 1999 US Open and 2005 Australian Open. Enditem