The shock Nadal move that could cost him World No.1

Rafael Nadal has put his World No.1 ranking in jeopardy after announcing he will skip the Asian leg of the ATP tour to recover from a knee injury.

The 32-year-old picked up the knee injury in the semi-final of the US Open against Argentine Juan Martin del Potro.

The decision comes as a shock and despite many thinking Roger Federer may be the man to claim top spot, it is sure to boost Novak Djokovic’s chances of ending the year on top of the rankings.

Rafael Nadal’s World No.1 ranking is in jeopardy. Pic: Getty

With Federer cutting the number of tournaments he plays – the Swiss only took part in events in Shanghai, Basel and the ATP finals after last year’s US Open – Djokovic is now favourite to unseat Nadal as world No.1.

Nadal was forced to retire during at Flushing Meadows with what he later said was tendinitis in his right knee.

Then injury will now keep him sidelined for next month’s tournaments in Beijing and Shanghai.

Djokovic, seeded sixth at the US Open, beat Del Potro in the final to claim his second grand slam title this year and rise to third in the rankings, behind Nadal and Roger Federer.

“I had to retire from the semi-finals of the US Open and this past Monday I was with doctors in Barcelona to review the situation with my knee,” Nadal wrote on Twitter.

Novak Djokovic is in the hot seat to claim the World No.1 ranking by the end of the year. Pic: Getty

“While my knee problems are nothing new, I have decided together with my medical and technical team not to participate in the Asian tour to recover.”

The Spaniard tops the world rankings with 8,760 points, 1,860 ahead of Federer and 2,315 more than in-form Djokovic.

with AAP.