Australia's Nick Kyrgios has pulled out of his quarter-final against Roger Federer at Indian Wells because of a bout of food poisoning.
The 21-year-old, seeded 15th, beat world number two Novak Djokovic in the previous round, but will not now face Australian Open champion Federer.
"At this stage we think it's food poisoning, and I'm praying it's nothing more," Kyrgios said in a statement.
Federer, 35, goes on to face Japan's Kei Nishikori or Jack Sock of the US.
The Swiss star's match-up against in-form Kyrgios was much anticipated, and he sent his support to the Australian on Twitter, saying: "Hope you feel better @NickKyrgios,"
Kyrgios added: "After a restless night of being sick I have nothing left and to play a great champion like Roger, I need to be at my best to have a chance."
"I don't take this decision lightly, these are the matches we train for but I'm in no fit state to take to the court. I'm sorry to the fans but I have to put my health first and I hope you understand.