"My long break from the game means I have to be careful about my preparations which will take a bit longer." Graf said. ''I don't want to put my good recovery in any danger by coming back too soon."
Graf, the Wimbledon champion, lost the No 1 spot to the Swiss teenager at the end of last month. The Hamburg tournament starts on 29 April.
Croatia's Goran Ivanisevic broke three little bones in the middle finger of his right hand but will try to continue playing in tournaments.
Ivanisevic, ranked No 5 in the world and winner of 19 career titles, slammed the door on his finger at his apartment in Split. Doctors suggested that Ivanisevic should take a one-month break from the game, but he said: "I have no intention to stay away for such a long time.''
Andrei Pavel, of Romania, caused an upset by defeating the Wimbledon champion, Richard Krajicek, yesterday in a second- round match of the Gold Flake Open event in Madras, India.
Pavel, who lives in Germany but plays Davis Cup for Romania, overpowered the Dutch top seed 7-5, 6-3, to move into the quarter-finals.Reuse content