Kei Nishikori withdrew from the Millennium Estoril Open on Tuesday, citing a right abductor injury.
"I am very disappointed to have to withdraw from Estoril. I came here early, took some days off and then had two very good days of practice," Nishikori said in a statement. "Yesterday, unfortunately, I stepped wrong and hurt my right abductor. We are doing checks and do not think it is serious, but unfortunately will not be ready to play a match in the next 48 hours.
"I wish Joao and the team a great tournament and hope to be able to come back here at some point in the future."
Roberto Carballes Baena will replace Nishikori in the draw as a lucky loser and play two-time Grand Slam finalist Kevin Anderson in the second round.
"I am very disappointed to have to withdraw from Estoril. I came here early, took some days off and then had two very good days of practice," Nishikori said in a statement. "Yesterday, unfortunately, I stepped wrong and hurt my right abductor. We are doing checks and do not think it is serious, but unfortunately will not be ready to play a match in the next 48 hours.
"I wish Joao and the team a great tournament and hope to be able to come back here at some point in the future."
Roberto Carballes Baena will replace Nishikori in the draw as a lucky loser and play two-time Grand Slam finalist Kevin Anderson in the second round.