Nadal drops out of Cincinnati Open with bad knee

LONDON, ENGLAND - JUNE 28: Rafael Nadal of Spain reacts during his Gentlemen's Singles second round match against Lukas Rosol of the Czech Republic on day four of the Wimbledon Lawn Tennis Championships at the All England Lawn Tennis and Croquet Club on June 28, 2012 in London, England. (Photo by Clive Rose/Getty Images)

CINCINNATI (AP)  - Rafael Nadal has dropped out of the Western & Southern Open because of a knee problem that forced him to miss the Olympics.

Nadal pulled out of the London Games because of a sore left knee, missing the chance to defense his title and serve as Spain's flag bearer in the opening ceremony.

He won the French Open for a record seventh time earlier this year but has been bothered by a problem with the tendon in the knee for weeks. He lost in the second round at Wimbledon and hasn't played since then, dropping out of the Olympics and the Rogers Cup this week. The Masters event in suburban Mason begins Sunday.

Nadal posted on his Facebook page Thursday that he is ``still not ready to play.'' The U.S. Open starts Aug. 27.