Nishikori retires injured at Halle

Halle - Japanese world No 9 Kei Nishikori was forced to retire injured in the second round of the Wimbledon warm-up tournament in Halle on Thursday. 

Nishikori, seeded third in the grass-court tournament, was trailing 3-2 to Russia's Karen Khachanov when he felt a pain in his hip. 

The 27-year-old Olympic bronze medallist had hip treatment courtside but in the end was forced to concede defeat. 

Wimbledon gets underway on July 3 in London.