Doubt has been cast on Dundalk's UEFA Champions League qualifier with Celje.
The SSE Airtricity Premier Division champions are due to travel to the neutral venue of Hungary on Wednesday-week (August 19) for their first qualifying round match.
The game won't take place in Slovenia as the country is not on Ireland's 'green list' for travel.
However, the start of the Slovenian season has been delayed by an outbreak of COVID-19 at three clubs.
The Slovenian FA have also decided to play all games behind closed doors until further notice.
The Slovenian PrvaLiga season was due to get underway this Thursday, but the start date has been put back to August 22.
Celje were due to open their season on Wednesday night against Cup-winners Mura, before playing Aluminij three-days before the Dundalk game.
Cases of COVID-19 first raised its head at Domžale earlier this month, but Aluminij have also reported cases as have Olimpija Ljubljana who announced three positive results on Tuesday.
"Due to contact with coronavirus positives, all players and the professional staff must be quarantined according to professional guidelines, the National Institute of Public Health told us", Olimpija said in a statement.
UEFA will be keeping a keen eye on events in Slovenia.
Earlier on Tuesday, KF Drita were forced to forfeit their Champions League preliminary round tie to Linfield after second player tested positive for coronavirus.
The Kosovar side were unable to fulfil the tie in Nyon, and so Linfield progress to face Legia Warsaw.
Under temporary UEFA rule changes, clubs unable to fulfil fixtures forfeit to their opponents.
The Slovenian FA has reminded clubs and players, "to act responsibly and to strictly observe the decisions and regulations of the NHS and the decisions of the competent state authorities.
"We will only be able to successfully face the challenges we are witnessing in these uncertain times with consistent respect for safety and health, professional conduct and constructive cooperation.
"Only in this way will we be able to ensure that the activities that are the foundation of our activity are carried out safely and fully."