Celtic say VAR in Scotland "needs urgently reviewed" after their unsuccessful appeal against the red card shown to Auston Trusty in their Scottish Premiership defeat by Hibernian, with the defender now to serve a three-match ban.
St Mirren were successful in challenging Richard King's sending off in Saturday's loss to Motherwell and his ban was overturned.
Trusty, 27, was dismissed with the score 1-1 at Celtic Park following an incident with Hibs' Jamie McGrath as the pair jostled at a corner. The defending champions lost 2-1.
The defender will be banned for three games, including Sunday's Old Firm derby at Rangers, before Scottish Premiership games away at Aberdeen and at home to Motherwell.
Violent conduct carries an automatic two-match suspension but Trusty incurred an additional one-match ban, having previously been sent off in the competition this season.
However, Trusty will be available for the Scottish Cup quarter-final away to Rangers on 8 March.
"We are hugely disappointed at today's decision, which will now result in Auston Trusty being suspended for three matches after an 'arm to arm' contact as he looked to release himself from being held prior to the ball coming into play - the kind of incident which features in games across the country week in week out," Celtic said.
"The match audio demonstrates that the referee saw the incident clearly. Immediately following the incident, the referee said: 'It's nothing I'm just going to speak to them' in terms of no further action being required.
"In discussions with Celtic manager Martin O'Neill after the match this was something he also confirmed.
"However, VAR again decided to intervene to 're-referee' an initial decision which had been made.
"While we await the written judgement, this and other decisions in the match and in other recent games demonstrate a serious issue with VAR and its current deployment which needs urgently reviewed."
St Mirren defender King, 24, was sent off in his side's 5-0 defeat by Motherwell in Paisley on Saturday. With his team trailing 3-0, the centre-back was involved in an incident with Callum Slattery and the Motherwell player fell to the ground.
Referee Calum Scott did not see the incident, issuing the red card on the advice of his assistant, and VAR did not intervene to ask him to review footage.
The independent panel ruled King should not have been dismissed and he will be available to face Livingston in Saturday's league game at Almondvale.