Nadal suffered an injury to his right wrist at home in Mallorca on July 29 whilst practicing for the US hard court season and he was advised by doctors to wear a cast for two to three weeks but the problem forced him to miss the Rogers Cup in Toronto and the Cincinnati Open.
The defending champion had hoped to recover in time before August 25, when the US Open gets underway at Flushing Meadows but announced on his Facebook page that he would not defend his title due to the injury.
Nadal said: “I am very sorry to announce I won’t be able to play at this year’s US Open, a tournament in which I’ve played in three consecutive finals.
“I am sure you understand that it is a very tough moment for me since it is a tournament I love and where I have great memories from fans, the night matches, so many things.
“Not much more I can do right now, other than accept the situation and, as always in my case, work hard in order to be able to compete at the highest level once I am back.”
The problem is a new one for Nadal to deal with after long-running battles with his knees. Though he plays left-handed, he has a double-handed backhand.
Nadal has not competed since he was beaten by Australian teenager, Nick Kyrgios, in the fourth round at Wimbledon on July 1.
He announced late last month that he would not be defending either his Rogers Cup title in Toronto or his Western & Southern Open crown in Cincinnati.
The World Number One has reached the final in his last three appearances at Flushing Meadows and on each occasion, he played Novak Djokovic.
He beat the Serbian in 2010 and 2013, and lost to him in 2011. Nadal missed the 2012 US Open because of a knee injury which kept him on the sidelines for nine months.
He won his 14th Grand Slam title on the clay of Roland Garros in May this year, but his pursuit of Roger Federer’s record 17 trophies will go on hold until the Australian Open in January, at least.
It is only the fourth time in the Open era, which began in 1968, that the reigning US Open men’s champion has been unable to defend his title.
Nadal’s absence means in-form world No 3, Roger Federer, who won the Cincinnati Masters on Sunday,would be seeded second behind Djokovic.