THE ASSOCIATED PRESS

MELBOURNE, Australia -- Rafael Nadal will miss up to four weeks of competition to recover from a knee injury that forced him to quit in the third set of his Australian Open quarter-final against Andy Murray.

The No. 2-ranked Nadal had his right knee assessed in Spain and was advised to rest completely for two weeks, then have two weeks of medical treatment before returning to tournament play, his management said in a statement Friday.

Nadal said it was not the recurrence of the tendinitis that sidelined the six-time Grand Slam singles champion for periods of 2009. He was unable to defend his Wimbledon title last year because of the tendinitis and has not reached another Grand Slam final since his five-set win over Roger Federer at last year's Australian Open.

MRI and ultrasound tests showed a small tear at the back part of Nadal's right knee, which can be treated with physiotherapy and anti-inflammatory treatment, Dr. Angel Ruiz-Cotorro said in the statement.

Nadal expects to miss the ATP tournament starting Feb. 8 at Rotterdam, where he lost the final to Murray last year.

"After two weeks and depending on the results of the different tests and controls, he will steadily resume his sporting activity with a total recovery time to resume competition in fours weeks," Ruiz-Cotorro was quoted as saying.

Nadal said he was happy the latest injury setback was not lingering tendinitis.

"I feel good and I am only thinking now of recovering well," the 23-year-old Spaniard said. "My main goal right now is to get ready again and fit to play the upcoming events once I am able to compete.

"It is a big disappointment for me not to be able to play at ... Rotterdam this year."

Nadal, who replaced Roger Federer in No. 1 spot for 46 weeks from August 2008 until July last year, said losing a few places in the rankings was not a concern for him.

"It is not important for me the ranking issue and losing a few spots, that's normal when you are not able to compete," he said. "For me it is more important to play well again and to have the good feelings on the court that I had in Abu Dhabi, Doha and also at the Australian Open where I played at the highest level."