Referees make mistakes - just as players and managers do. 

That's the message from Philippe Clement as he gears his Rangers side up for the Old Firm derby with Celtic this weekend.

Much has been made about the appointment of John Beaton by the Scottish FA for the powderkeg clash.

Just last month the official was branded 'incompetent' by Brendan Rodgers in an outburst following his side's 2-0 loss to Hearts.

Conspiracy theories regarding the SFA's referees have surrounded this fixture, and Scottish football as a whole, for many decades.

And as Rodgers today labelled Beaton as 'one of the best in Scotland,' Clement was equally keen to cool any discourse about the focus on the man in the middle for Sunday.

He told Sky Sports: "I want my players to only be busy with the football and with our football, not with the rest. Not with the referees, not with the opponents, not with the crowds or noise around. We need to be focused on ourselves and that's what we need to do.

"For sure here, it's a little bit of a special city in that way. Everyone is looking back to the past, speaking about referees that made a wrong decision against their team in 1993 or 2008 and because of that they are not competent to do the game. In the end, we will not have a game without referees. That's not possible.

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"The referees are good, they work hard, they make mistakes like we make mistakes also. The players make mistakes, the managers make mistakes, but they want to do good for the game and they are important for the game also."

Rangers were left furious with Willie Collum following the winter derby at Celtic Park. 

He was on VAR duty that day, and there was a significant uproar caused when he ignored their claims for a penalty against Alistair Johnston for handball. It later emerged Abdallah Sima had been in an offside position in the attacking phase of play.