Australian Open champion Marat Safin has not fully recovered from a knee injury and will miss next month's Masters Cup in Shanghai.
Russian tennis chief Shamil Tarpishchev, who is also the country's Davis Cup captain, said on Saturday that Safin would rest for the remainder of the year in order to be fit for next season.
"This is the best thing for him to do, not to play," Tarpishchev said.
"He must first get 100 percent healthy before stepping on the court again. The most important thing is to prepare well for the Australian Open, where he must defend his title."
The world number five has been troubled by a ligament tear in his left knee since Wimbledon which also forced him to withdraw from the US Open.
He has not played since losing in the quarter-finals of the Cincinnati Masters Series to American Robby Ginepri in August.
The Australian Open begins on January 16.
Safin's participation in the Hopman Cup, to be played in Australia from December 30 to January 6, is also in doubt.
He is due to partner Svetlana Kuznetsova for Russia in the annual mixed team event.