Novak Djokovic of Serbia lies injured on the floor during his Davis Cup World Group tennis semi-final match against Juan Martin Del Potro of Argentina in Belgrade. Picture - Reuters.

World number one Novak Djokovic will miss the Shanghai Masters this week, following his withdrawal from the China Open last week, after aggravating his back injury in the recently concluded Davis Cup.

The 24-year-old aggravated the back injury, initially sustained during his US Open triumph, when playing Argentina in the Davis Cup semi-final. It led to his withdrawal from the China Open, which he had won last year, and he has now confirmed he will also be missing the Shanghai Masters, as he hasn't sufficiently recovered yet.

I did another check this week and the results are not good so I need to continue my rehabilitation. Djokovic said.

The injury, a slight rupture of a back muscle, forced him to forfeit the Davis Cup semifianl against Argentine Juan Martin del Potro which he was trailing 6-7 0-3. It helped Argentina win the tie 3-1.

The Shanghai Tournament will also be without 17-time Grand Slam champion Roger Federer, who pulled out in order to rest and recuperate after an hectic summer.