Tennis news - Injured Rafael Nadal forced to withdraw from Beijing and Shanghai

The 17-times Grand Slam champion was forced to retire from his US Open semi-final with Juan Martin del Potro earlier this month, and has confirmed on Twitter that he will not be back in time for the Asian swing.

Nadal, 32, was due to defend his China Open title in early October while he lost to Roger Federer in the final of the Shanghai Masters event a year ago.

"Hello everyone, as you know I had to retire from the party of semi-finals in the US Open and this past Monday I was in Barcelona watching with doctors the situation of my knee," wrote Nadal.

"While the annoyances on my knee are nothing new, we have decided together with my medical and technical team not to participate in the Asian tour to recover the knee the way we have always done.

"I'm sorry I can't be with all the fans in China who are so many and with the organizers of the Beijing and Shanghai tournaments that have always given me and my team so much attention."

Wimbledon and US Open champion Novak Djokovic will hope Nadal's absence can help his push to become the prestigious season-ending number one at the Paris Masters and World Tour finals in November with Nadal's injury opening the door for his return to top spot.

Nadal was in trouble early on against Del Potro due to his knee problems, but he tried to persevere until retiring after dropping the first two sets.

While leading 4-3 in the first set Nadal got his right knee taped, before later ripping it off and having it re-taped early in the second during a medical timeout in which he also had his leg massaged.

Nadal tried to play through the pain but the Spaniard removed his headband and said he could not continue trailing 7-6(3) 6-2.