Korda says Australian Open-ending injury first appeared in Adelaide

Korda retired while trailing Karen Khachanov 7-6(5) 6-3 3-0 at Rod Laver Arena, dashing his hopes of emulating his father Petr, who won the title at Melbourne Park in 1998.

The American said he was struggling to even hold the racket after making a forehand in the second set.

"I had it a little bit in Adelaide a couple weeks ago, but then it went away," said Korda, who lost to Novak Djokovic in the final of the Australian Open warm-up tournament.

"During the matches, it was completely fine. Then just one kind of mishit return, and it started to bother me a lot of after that."

The American 29th seed said he knew right away he was in trouble.

"I kind of felt that spot that I was feeling before," Korda said. "Some forehands I couldn't even hold the racket. Volleying was almost impossible for me.

"Today was tough, but hopefully it's nothing serious and I can take care of it so I don't have it in the future."

Korda, who stunned former US Open champion Daniil Medvedev and Polish 10th seed Hubert Hurkacz to reach the quarters, said there were plenty of positives from the Grand Slam despite the nature of his exit.

"I have always been very close to winning the big matches, but now I'm getting through them," Korda said. "I think that's a huge lesson I have been learning. I'm really proud of myself.

"I'm going to keep on trying to do the same thing, keep on mentally being the same way. I think I can do some really big things in the near future.