Rangers vs Celtic has been delayed following huge pyro displays from both sets of fans.
Referee Don Robertson was forced to halt kick-off as smoke filled the Hampden Park skyline.
Robertson was called in late to referee the clash after Willie Collum was injured during the warm-up.
The whistler was set to take charge of the powderkeg fixture but has pulled out right before kick-off due to a calf strain.
Daniel McFarlane and Dougie Potter are the assistant referees for the match with Steven McLean in the VAR room alongside Frank Connor.
