According to Donghyun's label Starship Entertainment, the idol bumped his head on a camera during his performance with 'The Unit' for the contestants' first song "My Turn", and went to the hospital to be checked up. The label said, "It seemed like his head was cut when he bumped into the camera. We've yet to received a more detailed examination." 

Hopefully Donghyun's injury isn't too serious, and fans will still be able to catch 'The Unit's winning male and female teams performing "My Turn" on 'Music Bank'.