Knee injury rules Nadal out of Cincinnati Open
Nadal had pulled out of the London Games as well due to the same problem.
Cincinnati: 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 defend his title and be 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, dropping out of the Olympics and the Rogers Cup this week. The Cincinnati event begins Sunday.
Nadal posted on his Facebook page Thursday that he is "still not ready to play."
The U.S. Open starts Aug. 27.