Barcelona - Japan's Kei Nishikori was forced to pull out of next week's Barcelona Open on Saturday, citing a wrist injury.
"I am very sorry to pull out of the Barcelona tournament," Nishikori, who won in Barcelona in 2014 and 2015, said in a statement.
"It's obviously one of my favourite tournaments and have great memories here the last years.
"Unfortunately my right wrist is not recovered enough to play here this week.
"I will fly back to Florida with my team and work on getting back on the tour as quick as possible."
Nishikori's withdrawal is a boost for Rafael Nadal's chances of claiming a 10th title in Barcelona as the Spaniard is now the highest seed in the bottom half of the draw.
Top seed and world No 1 Andy Murray announced on Friday he would continue his comeback from his elbow injury in the Catalan capital and will face either Bernard Tomic or Dustin Brown in the second round.