The Bundesliga game between VfL Bochum and Borussia Mönchengladbach was canceled on Friday evening due to a cup being thrown.
In the 68th minute, assistant referee Christian Gittelmann was hit in the head by a drink cup that was thrown from the stands.
Referee Benjamin Cortus then immediately stopped the game.
Gittelmann kept rubbing the painful area on his head.
The team of referees retired to the catacombs of the stadium.
The Gladbach players followed shortly afterwards.
The Bochum players around goalkeeper Manuel Riemann went to the supporters and tried to influence them and then later left the field.