Dundee United are to lodge an official complaint about referee Mike McCurry's handling of Rangers' 3-1 victory.
United appeared to be denied a penalty and had a goal chalked off for offside in an explosive second half.
"We had a blatant penalty and he bottled it," said United manager Craig Levein after Saturday's game.
"If it's not a level playing field and, if we don't get the decisions, blatant, important decisions then what is the point of turning up?"
The defeat has hit United's hopes of finishing third in the Scottish Premier League and clinching a Uefa Cup spot for next season.
"I thought Mike McCurry had the balls to stand up and give these decisions, but he bottled it," Levein said.
"Not only is it a penalty kick, but it's a sending off for Davie Weir. But he didn't want to do it because this game meant so much to Rangers."
Levein said he asked the referee what was the point of his players turning up if they were to be the victims of such decisions.
"Anybody who is of a fair mind watching that today would see that we had no chance of winning that.
"We get a perfectly good goal chalked off and a blatant penalty, with not even a decision to make, and it should've been a sending off."
Levein's strong words could lead to disciplinary action from the Scottish FA.
But United chief executive Stephen Thompson has promised to back his manager "all the way".
Television personality and ardent United fan Lorraine Kelly phoned BBC Scotland's Your Call radio programme to weigh into the debate.
"I've gone from being scunnered and angry to being weary of it," he said.
"It just happens far too often. I am a Dundee United fan and we were robbed. "We have to stop whinging and moaning about it and do something about our referees."
I voted yes they will complain! Well done United
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