Nick Kyrgios was forced to pull out of his Japan Open quarter-final just minutes before he was due on court.
The Australian tennis star, 27, was due to face American Taylor Fritz but withdrew with a knee problem.
The Wimbledon finalist has also withdrawn from the doubles after reaching the semi-finals with Thanasi Kokkinakis.
“It’s heartbreaking. When the body lets you down it’s not a good feeling,” Kyrgios said.
“I have to be smart and after hitting with Thanasi today I feel that this is the best thing to do. I have a couple of tournaments at the end of the year and wanna do well there.
“I actually was dealing with a bit of a knee issue around the US Open time, and got back home, and probably didn’t take enough time off.”
Kyrgios, the world number 20, was among the favourites to win the singles tournament and was the top seed in the doubles draw.
Fritz now advances to the semi-finals.