Chris Vermeulen was forced to sit out the second World Superbike race of the weekend at Brno after his troublesome elbow injury flared up once more.

The Australian, who has been battling knee injury woes for more than a year now, first injured the elbow in an accident at Monza in May, but a fall during first free practice at Brno would cause it to swell up again.

Though Vermeulen soldiered on for much of the weekend and finished the first race in 18th, he chose not to risk it for the second race.

"I have been struggling all weekend since the crash on Friday morning," the Kawasaki rider said. "My elbow had really swollen up and my back was sore after race one so together with the team we took the decision not to take any more risks and not ride in race two."