Former world number one Serena Williams [ Images ] has pulled out of the French Open [ Images ] because she has not fully recovered from health issues, organisers said on Thursday.

"American Serena Williams, who has not fully recovered from health problems -- pulmonary embolism, foot injury -- has pulled out," organisers said in a statement.

Serena, who has not played since last July, has dropped to 17th in the WTA rankings. She won the French Open in 2002.

Her sister Venus is a major doubt for the May 22-June 5 tournament having not played since January because of a hip injury.

Organisers also confirmed that former world number one Dinara Safina [ Images ], who is taking an indefinite break from the sport, and Argentine Davis Nalbandian had pulled out of the tournament.