On BBC Sport:
Dundee United manager Peter Houston says he fears for the game if every penalty conceded results in a red card.
Houston did not dispute Rangers’ three spot-kick awards as United had a trio of players sent off in a 4-0 defeat.
But he said: “I worry about the game and where it’s going to if we are going to have straight red cards for every incident that’s happening in the box.
“I am frustrated that we have had three players sent off in a game when there was hardly a tackle put in.”