Rafael Nadal will not defend his title at the US Open because of an injured right wrist.
The 28-year-old left-hander sustained the injury during practice last month and has been training with a cast on his right wrist, forcing him to miss the Rogers Cup in Toronto and last week's Cincinnati Open.
Australian Open - 1
French Open - 9
Wimbledon - 2
US Open - 2
"I am very sorry to announce I won't be able to play at this year's US Open a tournament on which I've played three consecutive finals in my last participations," he said on his official Facebook account.
The 27-year-old Spaniard was hurt on July 29 while practicing on his home island of Mallorca.
The next day, Nadal said he had been told by doctors to wear a cast on his wrist for two to three weeks, but he hoped to be able to return in time for the US Open.
The second-ranked Nadal plays left-handed, but he uses a two-handed backhand.
It's only the fourth time in the Open era, which began in 1968, that the reigning US Open men's champion is not in the field.
Nadal won his second championship at Flushing Meadows in 2013, part of a run of reaching the final in each of his last three appearances in the US Open. He beat Novak Djokovic to win the titles in 2010 and 2013 but lost to the same opponent in 2011.