The FAI have postponed Shamrock Rovers' next three fixtures after the club confirmed two positive COVID-19 cases.
Striker Aaron Greene returned a positive test after Monday's latest round of screening.
The SSE Airtricity Premier Division leaders also revealed that midfielder Jack Byrne tested positive while on Republic of Ireland duty.
Byrne was absent from the Ireland squad that travelled to Helsinki for Wednesday's UEFA Nations League defeat to Finland.
Rovers say "several other players" must also now isolate having been deemed close contacts of Greene's.
Stephen Bradley's side were due to welcome Derry City to Tallaght Stadium on Friday evening, a game that could have sealed the Premier Division title if Bohemians dropped points at Dundalk.
The FAI say that "due to the high number of close contacts within the squad", Rovers' next three games will all be rearranged.
As well as Friday night's game with Derry, their October 19 trip to Finn Harps and the October 23 visit of St. Patrick's Athletic will need to find new dates.
With the rise in COVID-19 cases across the country, SSE Airtricity League clubs have begun to feel the sting of the virus.
Coupled with Dundalk's involvement in the UEFA Europa League group stage, the impact of the virus was such that the FAI decided last week to extend the season.
The Premier Division season will now conclude on Sunday, November 8 whilst the First Division season will now finish on Tuesday, October 27.