MIAMI (AFP) - Japan's Kei Nishikori took to Twitter Friday to announce his withdrawal from the ATP Miami Masters, where he had been due to take on Novak Djokovic in the semi-finals.
"Very sorry to say that I have to pull out today," said Nishikori. "Very disappointed and I am obviously very sorry for any fans that wanted to come out for this match."
The 24-year-old Japanese player, who upset Swiss great Roger Federer to reach the second Masters semi-final of his career, didn't specify his reason for pulling out, but tournament officials later tweeted that he had a groin injury.
His withdrawal gives world number two Djokovic a walkover into Sunday's final, where he'll face either world number one Rafael Nadal or Czech Tomas Berdych.
Nishikori secured his second top five win in succession when he rallied from a set down to beat Federer 3-6, 7-5, 6-4.
He had saved four match points to beat world number five David Ferrer of Spain 7-6 (9/7), 2-6, 7-6 (9/7) in the fourth round.
It was a disappointing end to the campaign for Nishikori, who was the first Asian player since Thailand's Paradorn Srichaphan in 2003 to reach the Miami semi-finals.
"I will work with my medical team to be back healthy as soon as possible," he said in a statement on his Facebook page.