Celtic and Aberdeen should not be playing matches this week after their players broke lockdown rules, First Minister Nicola Sturgeon has said.
Celtic defender Boli Bolingoli flew to Spain without the club's knowledge, failed to quarantine, then played in Sunday's match against Kilmarnock.
Ms Sturgeon said this was a "flagrant breach" of the guidelines.
The previous weekend eight Aberdeen players broke lockdown regulations by visiting a bar together.
Ms Surgeon told her daily briefing: "As a minimum, you should not be expecting to see Aberdeen or Celtic play in the coming week."
"Consider today the yellow card," she warned.
"The next time it will be the red card because you will leave us with absolutely no choice."
'Beyond explanation'
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.
Two of the players later tested positive for the virus, while six are currently self-isolating.