Spain's Rafael Nadal, the world's No. 1 player, said in a statement posted on his web-site that he planned to skip the Tennis Masters Cup in Shanghai starting on Sunday due to a knee injury, Spain's EFE news agency reported on Tuesday.
Nadal said he wanted to recover from the knee injury, which forced him to retire from his quarterfinal match against Russia's Nikolay Davydenko on last Friday in Paris, so he could focus on Spain's Davis Cup final against Argentina in Mar del Plata Nov 21-23.
The Tennis Masters Cup, the sport's year-end championships, trails only the four Grand Slam tournaments in terms of ranking points and prestige.
The tennis star said he would not be in Shanghai and had made a personal decision to rest up for Davis Cup play.
"I have decided not to take part in the Masters Cup in Shanghai. It's one of the hardest and most difficult decisions I've had to make in my career because of the event's importance and, especially, because I won't be with the fans in China who have shown so much affection for me all these years, as well as for the organisers who always treated me in a special way," Nadal said in the statement.
"I know many people had been speculating about this news and I believe that despite not undergoing any tests, I can say for now that I am making the right decision," Nadal said.
"I am doing this because I want to recover so I can prepare for my country's important meeting in Mar del Plata (against Argentina in the Davis Cup final). If I'm not going to Shanghai, it's also because of that," the Spanish tennis star said.
The 22-year-old Nadal has had his most successful year on the tour in 2008.
In August, Nadal became the new world No. 1 tennis player, knocking Switzerland's Roger Federer out of the top spot in the ATP rankings for the first time in 237 weeks.
Nadal, who won the gold medal in singles at the Summer Olympics in Beijing, is only the third Spaniard to be No. 1 in the world.
The Spaniard, the seventh-youngest man to be ranked No. 1, won his fourth French Open title in June and his first-ever Wimbledon title the following month.
Nadal, who won Spain's first Olympic gold in tennis by defeating Chile's Fernando Gonzalez 6-3, 7-6 (2), 6-3, also advanced to the semi-finals of the US Open for the first time in his career with a 3-6, 6-1, 6-4, 6-2 victory over American Mardy Fish.
The Spaniard - whose previous best result at the US Open had been a quarterfinal appearance in 2006 - lost in the semi-finals to Scotland's Andy Murray.