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.
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.
