Korda says could barely hold racquet in painful Australian Open exit
The 22-year-old American hurt himself in the second set against Russia's Karen Khachanov and called it quits when trailing 7-6 (7/5), 6-3, 3-0.
He said he first felt the injury while playing the Adelaide International this month, where he made the final and forced a championship point before being beaten by Novak Djokovic.
But it had not bothered him in the opening four rounds at Melbourne Park until he hit a return in the second set.
"I had it in Adelaide and then it went away completely. Now it just came back out of nowhere," he said. "I have never had any wrist issues before.
"I knew kind of what it was right away, right when I hit the return. I kind of felt that spot that I was feeling before.
"Some forehands I couldn't even hold the racquet. Volleying was almost impossible for me, so it was a little tough."
Despite the pain of defeat, it was a hugely successful Australian Open for Korda, who made a Grand Slam quarter-final for the first time.
Along the way he stunned two-time losing finalist and seventh seed Daniil Medvedev and world number 10 Hubert Hurkacz.
"There is a lot of positives. I mean, way more positives than even negatives," he said.
"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.
"Still a great tournament. My first quarter-final in a Grand Slam. You know, I'm going to go forward with my head high and keep working."
Korda, whose father Petr won the title in 1998, said he took particular confidence from pushing Djokovic hard in Adelaide and beating top 10 players at Melbourne.
"A lot of confidence now. I mean, I have always been very close to winning the big matches, but now I'm getting through them," said the American, whose sisters Nelly and Jessica are both champion golfers.
"I think that's a huge lesson I have been learning, and going forward 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. You know, I think I can do some really big things in the near future."