Shinya Nakano is to return to his native Japan to have medical tests after neck pains prevented him from competing in the second World Superbike race at the Nurburgring.

The former MotoGP rider had been enduring a dismal weekend in Germany, failing to reach Superpole before retiring from the opening race while he was labouring outside the points.

Complaining of pains in his neck, although he took a trip to the Clinica Mobile, Nakano felt he was unable to line up for the second race and will now leave for Japan to have medical tests to determine the exact nature of the injury.

Nakano, in his first season of World Superbike racing, is yet to show the same kind of form as team-mate Max Biaggi on the Aprilia this season, and is currently languishing in 13th position overall.