Halle Open
Nishikori opened his grass-court season by participating in the Halle Open where he reached the semifinals, only to retire in his match against Andreas Seppi down 1–4 in the first set due to his calf injury which he attained in his quarterfinal match. Nishikori decided to play Wimbledon, and he reached the second round by beating Simone Bolelli in five sets for the second straight year but then withdrew from his second round match against Santiago Giraldo, due to his calf injury acting on him again during his first round match.