Thanasi Kokkinakis will have an MRI scan in London to determine the extent of the injury that's wrecked his Wimbledon hopes - and he fears the worst.
The joy of his remarkable triumph over 17th seed Felix Auger-Aliassime from two sets down on Wednesday turned to misery less than 24 hours later in his second-round match against French qualifier Lucas Pouille.
Trailing 2-6 7-5 4-2, Kokkinakis - a big man who's often talked of how tentative he feels with his movement on grass courts - slipped and twisted his left knee while trying to retrieve a forehand.
The 28-year-old tumbled over, clearly in agony, while former French No.1 Pouille crossed the court to help attend to him.
Kokkinakis eventually soldiered on for one more game, but at 5-2 down limped across to tell Pouille there was no way he could continue.
"It was a tricky match. It started well but there was a weird kind of energy out there, it felt strange," Kokkinakis said.
The Australian had been unhappy with a heckler in the crowd the previous day who had badgered him and Auger-Aliassime to play on after rain had made the surface treacherous.
A fortnight ago Kokkinakis suffered a similar tumble at the Queen's Club Championship on a wet court, which caused a medial collateral ligament injury that kept him out of action for a week.
He also had sprained his troublesome left knee two years ago at a pre-Wimbledon Challenger tournament in nearby Surbiton, which cost him a month out of the sport.
"He was starting to play some good tennis and I was trying to rally and just slipped and hurt my knee," he said.
"I'm going to see the severity after some scans - but I know I've done a similar injury to what I did at Queen's Club.
"But it feels a bit worse, that's my gut feeling."
Kokkinakis had planned to play a hard-court tournament in Atlanta next.
"But now I've got to have an MRI to see if that's going to be possible or not," the world No.93 said.
