NEW YORK — Rafael Nadal’s Grand Slam count will stay stuck at 11 for now, sidetracked by another knee problem.

The third-ranked Spaniard withdrew from the U.S. Open on Wednesday. Tendinitis has kept him out of action since his stunning loss at Wimbledon in late June.

The injury already forced him out of the London Olympics, where he was supposed to defend his title and carry Spain’s flag in the opening ceremony.

“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.

Nadal is still only 26, but the withdrawals raise questions about the future of a player who has had recurring knee problems in the past.

His 11 Grand Slam titles include a record seven on the red clay of the French Open, yet his hard-charging, hard-hitting style of play takes a toll on his body, particularly his knees.