Ally McCoist has branded Don Robertson's decision to rule out Kemar Roofe's goal during yesterday's Old Firm match as "appalling".

The referee initially allowed the goal to stand, however, a short while later was advised by VAR to check for a potential foul in the build-up.

Cyriel Dessers dispossessed Gustaf Lagerbielke deep inside Celtic territory. The Rangers striker broke clear with the ball before playing in Roofe, who slammed home to send the packed Ibrox crowd wild.

VAR Alan Muir called Robertson over to the pitchside monitor. As is normally the case, the on-field official changed his mind, and a foul was awarded to Celtic, with the score remaining 0-0.

The hosts went on to lose the game by a single goal, which was scored by Kyogo just before half time.

McCoist reckons it was one of the worst derby encounters for some time, as he described both teams as "bang average".

But the former Gers and Scotland international could not wrap his head around that decision, as he slammed Robertson live on air this morning.

He told talkSPORT breakfast: “Rangers disallowed goal, it is an absolutely appalling decision. Cards on the table, I thought both teams were bang average at best. It might be the worst Rangers and Celtic teams in a while.

“The only bit of real class in the game was the finish from Kyogo. Callum McGregor was excellent first half and the finish was superb but deary me, how someone in VAR can pull the referee over there.

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“Dessers goes in and puts his foot down. The big Celtic centre back is dallying on the ball and kicks his foot, goes down, Dessers runs away and squares it, and Roofe scores and he gives a free kick against Dessers. It’s the ref's fault after he goes over to VAR, who have already made a mistake. The one thing it is not is a clear and obvious error.

“Someone is busy on VAR and he puts the ref in a position who sadly wasn’t strong enough to stay by his convictions. It’s not the first time we’ve seen it.”