Rafael Nadal has been out of action since before the Olympics and will be out for up to the next two months due to a knee injury.

The No. 3-ranked player in the world announced in a website posting linked to his Twitter feed that he has a torn patella tendon in his left knee.

"I have to recover and I'll be back once the pain is gone," Nadal said according to the website. "I have missed the Olympics and the U.S. Open in the last few weeks, two of the most important tournaments of the year and 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."

The last time Nadal played was at Wimbeldon where he lost in the second round against Lukas Rosol.

After announcing he was missing the Olympics, Nadal was hopeful that he could return this year for the U.S. Open, but his knee wasn't fully healed in time.

"I feel better after the meeting with my doctors and happy knowing that the evolution of the past weeks has been positive and surgery has been avoided," said Nadal according to the Associated Press.

The injury also means he will also miss playing in the Davis Cup against the U.S. for Spain. The defending champion Spanish team was finalized last week and includes David Ferrer, Marc Lopez, Nocolas Almagro and Marcel Granollers.

They will take on the American team led by John Isner and Sam Querry along with twins Bob and Mike Bryan.

While many have speculated that Nadal's knee issues could be the beginning of a decline, the Spanish star has battled back from serious injuries during his career. After suffering a knee injury in 2008 Nadal came back to win the 2009 Australian Open.

Nadal is considered to be the world's top clay court player and won the French Open this year for his 11th career Grand Slam championship.