Rafael Nadal withdrew from the U.S. Open Wednesday, dropping out of the last Grand Slam tennis tournament of the year due to injury.

Nadal cited left-knee tendinitis as the reason he’s not playing. The third-ranked Spaniard hasn’t played a match since June 28, when he was upset in the second round of Wimbledon by 100th-ranked Lukas Rosol.

"I am very sad to announce that I am not ready to play the US Open in NY. Thanks to my fans for their support and specially, the new yorkers," Nadal wrote on his Twitter account.

The 26-year-old Nadal also pulled out of the London Olympics, and was supposed to carry Spain's flag in the opening ceremonies.

Nadal won the 2010 U.S. Open to complete a career Grand Slam and was the runner-up to Novak Djokovic last year.

Play in the two-week tournament begins at Flushing Meadows on Aug. 27.