Li Na will take a break from tennis otherwise the sport will "kill" her after she was sent packing by British teenager Laura Robson.
Ninth seed Li was beaten in the third round 6-4, 6-7 (5-7), 6-2 by 18-year-old Robson, the world number 89, who had also defeated triple US Open champion Kim Clijsters in the previous round.
"I can't go back on the practice court straightaway. I have to take some days off otherwise this will kill me," said Li, 30.
The defeat meant it is the first time since 2008 that Li has not reached at least the quarter-finals at any slam during a season. "I will have to talk to my team," she said. "Maybe they can see things clearer on the court and we can plan the next step." Robson becomes the first British woman to make the last 16 in New York since Jo Durie in 1991. She will face defending champion Samantha Stosur of Australia for a place in the quarter-finals.
She is also the first British woman in the last 16 of any grand slam since Sam Smith reached the Wimbledon fourth round in 1998.
Li said: "She has a big serve but I made most of the mistakes and that gave her more confidence and let her think that she could beat me.
"I gave her a lot of free points. I wasn't happy about the way I played."
Li believes Robson can pose a tough challenge for Stosur. "If she continues like this, then she can beat other players. It's up to her. It all depends on the opponent."
Robson, the youngest player in the world top 100 and the 2008 Wimbledon junior champion, showed few signs of nerves as she swept into the fourth round of a major for the first time.
"It was really tough," said Robson, who said she will maintain her positive approach when she faces Stosur. "I have nothing to fear."