Andy Roddick was forced before his second round start at the Madrid Masters on Wednesday after unsuccessfully trying to overcome a stomach virus.
The pullout from the fifth seed came before his opening match against Madrid’s Feliciano Lopez.
“I was up about 24 hours between Sunday and Monday night with all the symptoms,” said Roddick, who won his last event, the Miami Masters, in early April.
“I played doubles on Tuesday but couldn’t focus on the ball. It was the same this morning after I warmed up.
“This is disappointing. I’ve worked hard after Miami, spending three weeks on clay in the States with my fitness trainer and coach.
“We’ll have to see what I can do to get a match or two,” said the player who is due for one exhibition match next week in Paris.
Roddick said he would be unlikely to join the US at the World Team Championships starting on Sunday in Dusseldorf, Germany, due to the fact that he might not be fit by then.
“I would have taken this virus any time over the past five weeks, but unfortunately I have it now,” he said. “I’ll have to see what I can do later for some matches.
The American said that despite the healthy setback, his French Open campaign is not lost yet.
“I went to Paris last year with only two match wins (from three played in Madrid). I still had my best Roland Garros ever (fourth round loss to Gael Monfils). I’d feel more worried about Paris if I’d not put in such good work on clay.”
Roddick said that his main goal was to rest and recuperate with the French Open starting on May 23.
