Rafael Nadal ruled out for another two months

Rafael Nadal has been ruled out for another two months as he struggles to overcome a knee injury.

The world number three has not played since a shock second-round loss to Czech Lukas Rosol at Wimbledon, missing the Olympics and the ongoing US Open as a result.

He will now sit out Spain's Davis Cup semi-final clash with the United States later this month as he continues his rehabilitation.

In a statement released through his official Twitter account, Nadal said: "I have missed the Olympics and the US Open in the last few weeks, two of the most important tournaments of the year and (ones) that I really wanted to play.

"I really want to be back competing and enjoying the tennis tour, but I have many years in front of me and my knee needs some rest."

PA