Rangers have called for the Scottish Football Association to review their disciplinary system "as a matter of extreme urgency" after Hampden chiefs refused to overturn Allan McGregor's two-game ban.
The Ibrox goalkeeper failed in his bid to appeal against a violent conduct charge after he was hit with retrospective punishment for kicking out at Aberdeen's Lewis Ferguson.
The Scotland number one rushed from his line to smother a loose ball during last week's drama-filled Pittodrie clash but left a straight leg hanging which collided with his Dons rival's shin.
Referee Bobby Madden took no action at the time but McGregor will now miss Saturday's home Ladbrokes Premiership showdown with St Johnstone and the William Hill Scottish Cup fourth-round replay against Kilmarnock.
SFA compliance officer Clare Whyte opted to refer the 37-year-old to a fast-track disciplinary hearing after reviewing footage of the incident.
That decision has now enraged Ibrox bosses, who were also left frustrated when they failed to have striker Alfredo Morelos' red card from the same Aberdeen match wiped out.
In a statement given to Press Association Sport, a club spokesperson said: "Rangers has no option other than to accept this decision.
"However, it is abundantly clear questions about the current disciplinary system, which we believe is flawed, must be posed.
"Rangers has been in dialogue with the Scottish FA on this topic for some time and would urge that the system is now thoroughly reviewed as a matter of extreme urgency."
The McGregor decision comes just 24 hours after Killie's Alan Power escaped a ban for kicking Rangers midfielder Ryan Jack in the face.
The Irishman was booked by referee Alan Muir during Saturday's cup stalemate at Rugby Park when his studs caught Jack on the cheek as they tangled for a bouncing ball.
Whyte decided against issuing a notice of complaint after deciding there was insufficient evidence to charge the former Lincoln midfielder.
