The 19-year-old from Majorca, whose tendinitis of the left knee caused him to pull out of the tournament in Vienna last week, said the pain in his knee worsened during the weekend.
Given a bye in the first round, Nadal said he would wait until tomorrow to see if the injury improved enough for him to play his second-round match against Victor Hanescu, of Romania.
Greg Rusedski may have bowed to superior opponents, but it is not often that the 6ft 4in British No 2 has to look up to a man on the opposite side of the net. That will be the case here today, when Rusedski plays the Croatian giant Ivo Karlovic.
The 6ft 10in Karlovic, best known for eliminating Hewitt, the defending champion, in the first round at Wimbledon in 2003, defeated Rusedski in their last match, at Washington during the summer.
Prior to that, Rusedski beat Karlovic twice last year, in St Petersburg and Moscow, from where Rusedski arrived here after a disappointing loss last week to a Russian qualifier, Igor Kunitsyn, in the second round of the Kremlin Cup.
A few weeks ago, Rusedski was at Tim Henman's shoulder in the world rankings, one place behind at No 29, and talked about finishing the season ahead of his British rival for the first time since 1997.
Yesterday the gap widened to 12 places, with Henman ranked 26th in spite of losing last week in the second round at the BA-CA Tennis Trophy, in Vienna, to the Czech Radek Stepanek.
Should Rusedski overcome Karlovic, he will play the second-seeded Andy Roddick in the second round. Rusedski's record against the American former world No 1 does not bode well. Roddick has won five of their five previous meetings, Rusedski's only success coming in their first match in the third round at Wimbledon in 2002.
That was the year Albert Costa won the French Open, and the 30-year-old from Lerida may have reached the end of the road yesterday after losing in the first round here to Agustin Calleri, of Argentina, 6-0, 7-6.
Asked if it was his to be his last match, Costa said: "Maybe, but I'm not sure. In the last three months I've only played two matches. But I want to keep the door open. I'm going to give myself a month's vacation, then I'll start thinking if I want to motivate myself."
* Hawk-Eye, the ball-tracking system used in cricket, has been approved by the International Tennis Federation and can now be used as an official on-court umpiring aid at any event to assist the umpire in line decisions. Rather than replacing line judges, Hawk-Eye will allow players to challenge a call via a screen to be placed by the umpire's chair.Reuse content