Nicola Sturgeon has issued a warning to Scottish football as Celtic and Aberdeen matches were called off after their players broke lockdown rules.
The first minister had said the two clubs should not play this week.
She said she did not want rule-abiding clubs and players, or fans, to be punished for the individual breaches.
But she warned: “Consider today the yellow card. The next time it will be the red card because you will leave us with absolutely no choice.”
Celtic defender Boli Bolingoli flew to Spain without the club’s knowledge, failed to quarantine, then played in Sunday’s match against Kilmarnock.
The previous weekend eight Aberdeen players broke lockdown regulations by visiting a bar together.
Ms Sturgeon said news of Bolingoli’s “flagrant breach” of the guidelines came through while the national clinical director, Professor Jason Leitch, was holding a meeting with the managers and captains of Scotland’s top flight clubs to reinforce the importance of the guidance.
What games were cancelled?
She said: “This is just not acceptable.
“Every day I stand here and ask members of the public to make huge sacrifices on how they live their lives. The vast majority are doing that and it’s not easy.
“We can’t have privileged football players just deciding that they are not going to bother. This can’t go on.”
The SPFL later agreed to the call offs and announced an “urgent package of measures” to prevent a repeat.
These include plans to punish players who break the rules, an “immediate” player education programme and an agreement to take part in promotional activity for the Scottish government’s FACT campaign.
Sport Minister Joe FitzPatrick said: “This latest example indicates that the current arrangements are not working as intended, and so clearly additional steps now need to be taken to ensure that the necessity of strict compliance with the rules is fully and properly understood.”
In the meantime Celtic and Aberdeen can train as usual but training and friendly matches will not be allowed.
Ms Sturgeon earlier indicated “very clear penalties” will be in place for players and clubs when the rules are breached.
The first minister said footballers are “talented, skilled, hard-working professionals” and “well-rewarded” role models.
But she added: “I don’t think it is too much to ask them to live up to that, and that is all we are asking.”
Prof Leitch said footballers who flout the regulations pose a risk to public health and endanger the return of all elite sport.
He said Bolingoli had travelled to a “high risk country” then went to work and “put both his team and the opposing team at risk of catching coronavirus.
“There has to be an implication of that in public health terms for those he was in contact with and their contact with others.”
Bolingoli played in Sunday’s match against Kilmarnock even though he should have been self-isolating.
The defender said he was “guilty of an error of judgement” and apologised.
Celtic apologised and said his actions were “beyond explanation”. All players and backroom staff have since been tested twice and returned negative results.
Eight Aberdeen players have apologised for visiting a bar at the centre of a Covid-19 outbreak in the city.
Two of the players later tested positive for the virus, while six are currently self-isolating.
A total of 165 positive cases of coronavirus are now linked to the outbreak in Aberdeen.
Dr Emmanuel Okpo, consultant in Public Health Medicine, said a lack of physical distancing had been “the significant factor in the spread of these cases”.
He said it was now likely that all licensed premises in the city had been affected.
“This is because physical distancing – or the lack of it – has come up repeatedly in our investigation,” he said.
“I would stress again that we must all take personal responsibility for physical distancing.”
For more updates on this story, see bbc.com.