Serbia's Novak Djokovic, the world number one seed, has a back injury and hinted to a Serbian paper on Tuesday that he may miss the China Open and the Shanghai ATP masters 1000 in October.
"I have a partial tear of a (back) muscle which needs rest, it is hard to say how much time off I need after only one exam, we will determine that in the days to come," Djokovic told the sports daily Sportske Novosti.
"What is certain is that I will not endanger my health to play in one or two tournaments," he was quoted as saying.
The world number one added that he would have to recuperate between three and six weeks which would see him cancel the China Open and the Shanghai masters which are both played in early October.
Last Saturday in the deciding fourth match of the Davis Cup match against Argentina in Belgrade, Djokovic was forced to concede the rubber against Juan Martin Del Potro because of the injury, which also played up during his US Open final win over Rafael Nadal.