Nicola Sturgeon has warned Lanarkshire could be moved into the toughest level of lockdown when existing restrictions are reviewed next week.
The First Minister said it was "not enough" to merely stabilise the number of people testing positive for Covid in Scotland as the winter months drew in.
North and South Lanarkshire are currently at level three - meaning non-essential shops and some hospitality businesses can remain open - but it had been widely tipped the counties would be placed at level four when a new five tier framework was first announced last month.
The Scottish Government will review the restrictions currently in place across the country next week - and the SNP leader said it was unlikely the question over Lanarkshire would be whether to move it up to level two.
Appearing before the Scottish Parliament's Covid-19 committee on Wednesday, Sturgeon said : "If you take an area down a level you open it up more, which is going to lead to increased transmissions.
"So the judgement has to be - has that area got to a low enough level to cope with that increased transmission.
"With Lanarkshire, I don't think it will surprise anybody to hear that I wouldn't expect the decision next Tuesday to be whether it will go from level three to level two - it will be will it stay at level three, or will it go to level four.
"That will come to a judgement of do we see cases continuing to decline, whether we think it is a significant enough decline, and the pressure on the NHS."
Any local authority area in Scotland placed in level four would see all hospitality businesses closed along with non-essential shops and hairdressers.
According to the Scottish Government's framework, schools would remain open and outdoor meetings would still be possible in groups up to six from two households.
More than 70% of Scotland's population is currently living under level three, including Glasgow, Edinburgh and Dundee and their surrounding areas.
The First Minister told MSPs that if a national lockdown was needed in the future it would see all of Scotland placed at level four.
But she added such a move may not require a "stay at home" message, similar to the instructions issued to the public in March.
