Livingston have returned no positive Covid-19 tests following Saturday's defeat by Hamilton Academical, after three of the visitors' players were initially found to have the illness.
On re-resting, the Hamilton trio returned negative results.
The Livingston squad were tested in two batches on Monday and Tuesday.
However, Hamilton's training has been suspended for a second day, with the squad to be tested again on Thursday before Saturday's trip to Kilmarnock.
Despite testing negative after NHS screening, the three first-team players have joined defender Lee Hodson in self-isolating, in line with government guidelines.
Hodson has stayed away from FOY Stadium since last Monday after his house-mate - St Mirren's Jak Alnwick - tested positive.
Hamilton say calling off training for a second day is a precautionary measure.
Likewise, Livingston chief executive John Ward tweeted that their screening has returned no positive tests.
However, St Johnstone manager Callum Davidson has warned it will be "really difficult" should clubs find themselves with a handful of players self-isolating at once.
"If a lot of clubs have people out, can't train, isolating, then it might become an issue," he said.
"I'm a positive person - you can't stop games for one or two cases per team. I think it's when it becomes a little bit more than that you have to have a look at it.
"If I've got my five best players out, I want the game off."
Do players need further testing if team-mates or backroom team return a positive result?
No. Clubs have to test once per week, within 168 hours of any game kicking off. Some are opting to do so twice but there is no obligation for further testing, even if there are positive results.
How do NHS Test and Protect ascertain if close contact becomes an issue?
The same general rules apply to footballing staff that the general public must follow, but when close contact is allowed on training field, GPS data is used.
If a person spends more than 15 minutes in close proximity with someone else, that is deemed close contact. The person in close contact, and their household, must self isolate for 14 days.
Uefa state games can be played as long as clubs have 13 players. Is this adopted by the SPFL?
Yes, but clubs can apply for games to be postponed if they feel they are being unfairly disadvantaged. These cases would be decided on a case-by-case basis by SPFL after consultation with the Joint Response Group and the Scottish Government.
Livingston have returned no positive Covid-19 tests following Saturday's defeat by Hamilton Academical, after three of the visitors' players were found to have the illness.
The Livingston squad were tested in two batches on Monday and Tuesday.
However, Hamilton's training has been suspended for a second day, with the squad to be tested again on Thursday before Saturday's trip to Kilmarnock.
Three first-team players have joined defender Lee Hodson in self-isolating.
Hodson has stayed away from FOY Stadium since last Monday after his house-mate - St Mirren's Jak Alnwick - tested positive.
Hamilton say calling off training for a second day is a precautionary measure and that there has been no indication of any further spread.
Likewise, Livingston chief executive John Ward tweeted that their screening has returned no positive tests.
However, St Johnstone manager Callum Davidson has warned it will be "really difficult" should clubs find themselves with a handful of players self-isolating at once.
"If a lot of clubs have people out, can't train, isolating, then it might become an issue," he said.
"I'm a positive person - you can't stop games for one or two cases per team. I think it's when it becomes a little bit more than that you have to have a look at it.
"If I've got my five best players out, I want the game off."
Do players need further testing if team-mates or backroom team return a positive result?
No. Clubs have to test once per week, within 168 hours of any game kicking off. Some are opting to do so twice but there is no obligation for further testing, even if there are positive results.
How do NHS Test and Protect ascertain if close contact becomes an issue?
The same general rules apply to footballing staff that the general public must follow, but when close contact is allowed on training field, GPS data is used.
If a person spends more than 15 minutes in close proximity with someone else, that is deemed close contact. The person in close contact, and their household, must self isolate for 14 days.
Uefa state games can be played as long as clubs have 13 players. Is this adopted by the SPFL?
Yes, but clubs can apply for games to be postponed if they feel they are being unfairly disadvantaged. These cases would be decided on a case-by-case basis by SPFL after consultation with the Joint Response Group and the Scottish Government.