Kei Nishikori has apologised to his fans after withdrawing from the semi-finals at the Miami Masters.

The Japanese player, who had been seeded 20th at the tournament, had been due to play Novak Djokovic in the last four, but had to pull out of the match with a groin injury.

Nishikori posted on his Facebook page: "Very sorry to say that I have to pull out today. Very disappointed and I am obviously very sorry for any fans that wanted to come out for this match.

"This tournament is very special to me and look forward to coming back in the years to come. I will work with my medical team to be back healthy as soon as possible."

Djokovic moves straight to the final, where he will face either Rafael Nadal or Tomas Berdych on Sunday.