Serena Pulls Out In Paris

Serena Williams called off her Grand Slam comeback because of a chest muscle injury pulling out of the French Open shortly before she was supposed to play Maria Sharapova in the fourth round.

``It's extremely disappointing,'' Williams said during a news conference at Roland Garros.

``But also, I made a promise to myself and to my coach and to my team that if I'm not at least 60 per cent or 50 per cent, then I probably shouldn't play.''

Williams, who has won 23 Grand Slam singles titles, said she can't hit serves because of a problem with her right pectoral muscle.

``The fact that I physically can't serve at all is a good indication that maybe I should just go back to the drawing board and stay positive,'' Williams said, ``and try to get better and not get it to a point where it could be a lot worse.''

The 36-year-old American was competing at a major tournament for the first time in 16 months and for the first time since giving birth to her daughter last September.

Williams said her chest began hurting in her third-round singles victory over 11th-seeded Julia Goerges on Saturday.