The grimaces on the face of Rafael Nadal were the first indication that something was wrong. Then he asked for a trainer to tape his right knee. Then, in the biggest sign of all, he allowed a ball to whiz past him without even a chase.
Then, in a moment of pique with the chair umpire in the second set, Nadal told him that he was going to retire.
A few games later, he did. After spending more than 17 grueling hours on court during the United States Open, his 32-year-old body gave way.
Nadal, the No.