Rangers have confirmed a Covid-19 outbreak has hit the club as they prepare for two key matches this week.
The Scottish champions say positive results were recorded, with those deemed close contacts also self-isolating.
The numbers affected - and whether they are players - has not been disclosed.
Steven Gerrard's side face Alashkert away in the second leg of their Europa League play-off on Thursday, followed by Sunday's Old Firm derby with Celtic.
A statement from the Ibrox club added: "We have followed best practice in our procedures and protocols.
"From the outset of the pandemic, Rangers has worked closely with the Scottish Government and Scottish football to ensure the health of our staff is protected at all times. We will continue to do so."
Rangers hold a 1-0 lead over Armenians Alashkert as they bid to reach the Europa League group phase for the fourth season running.
They then welcome rejuvenated Celtic to Ibrox for the opening Old Firm derby of the Scottish Premiership season.