Ranger' Europa League rivals Standard Liege have been rocked by six positive Covid-19 tests.
The Belgians now face taking on Lech Poznan this Thursday with a depleted squad after captain Zinho Vanheusden also suffered a serious injury.
Collins Fai, Konstantinos Laifis, Damjan Pavlovic, Eden Shamir, Moussa Sissako and Abdoul Fessal Tapsoba have all been forced into isolation.
A club statement said: "The results of the latest Covid-19 tests unfortunately indicate that 6 Red players are positive: Collins Fai, Konstantinos Laifis, Damjan Pavlovic, Eden Shamir, Moussa Sissako and Abdoul Fessal Tapsoba.
“These players will therefore not be part of the Standard de Liège delegation which will fly to Poland on Wednesday morning.”
On paper, the development looks unlikely to disrupt Standard's squad to any great extent.
Only Fai and Laifis featured during the club's 1-0 win over Oostende at the weekend, the latter from the bench.
The remaining four failed to make the weekend squad and have not been in regular contention for Phillippe Montanier's side.
The outbreak does not appear to have, as yet, had a wider impact on the squad with no indication that other players will be compelled to quarantine as a precaution.
Rangers defeated Standard 2-0 on Group D's opening night and the teams are scheduled to meet again at Ibrox on December 3.
