Bangkok - Next week's Thailand Open lost top seed Rafael Nadal as the Spaniard withdrew on Sunday with a continuing knee injury. The world number two would have been making his first appearance in the Thai capital, but will be unable to play due to a lingering case of tendinitis in his knees.
The problem affected the three-time French Open champion at the US Open, where he went out in the fourth round in some pain to compatriot David Ferrer.
Officials said that Nadal remains at home on the island of Mallorca for treatment.
Since losing the Wimbledon final to Roger Federer, Nadal has played in only four events, winning on clay in Stuttgart, reaching the Montreal semi-finals and losing in his opening match in Cincinnati before the US Open.
The Thai event will begin on Tuesday for a second straight year due mainly to scheduling conflicts with players coming in from weekend Davis Cup play.
Serb Novak Djokovic is top seed ahead of 2004 finalist Andy Roddick with each of them playing Davis Cup matches in Europe.