Liverpool’s Champions League group game with Midtjylland may be moved to Germany because of Covid-19 restrictions in Denmark.
Jurgen Klopp’s side are scheduled to play the Scandinavians on Dec 9.
Travellers returning from Denmark are expected to quarantine, so Uefa is exploring alternative venues.
Dortmund has emerged as a possibility if the Danes are unable to host the Premier League champions.
It is the latest Covid disruption for Liverpool, whose striker Mohamed Salah must remain in self-isolation in Egypt along with Arsenal’s Mohamed Elneny after another positive test for the virus.
The Egyptian Football Association has confirmed the latest results, preventing Salah and Elneny from returning to their clubs ahead of the preparations for this weekend’s Premier League fixtures.
Managers Jurgen Klopp and Mikel Arteta must press ahead in the expectation they will not be able to call upon the players according to the protocols.
The pair first tested positive earlier this week and will not be able to leave the country without testing negative. Salah has now given three positive tests in the last few days.
Liverpool’s starting line-up will be severely impacted after another debilitating international break. Jordan Henderson is a doubt for the visit of Leicester City after suffering a groin issue playing against Belgium last weekend.
Henderson was forced off at half-time in England's Nations League defeat and released from international duty before Wednesday's games with Iceland. That follows the serious knee injury sustained by Joe Gomez before the international friendly with the Republic of Ireland.
Klopp is already without Virgil van Dijk for the long term. Joel Matip has returned to training, but there was no sign of Fabinho when the club released pictures of the first training session at the new AXA training centre on Tuesday.
Thiago Alcantara has not featured since being injured in the Merseyside derby, Alex Oxlade-Chamberlain is yet to join group training, and even youngster Rhys Williams was released from England Under-21 duty as a precaution due to a sore hip.
Salah and Elneny are among several high-profile players to test positive for Covid-19 during this break.
Irish duo Matt Doherty and James McClean had to self-isolate, and Uruguay and Atletico Madrid striker Luis Suarez will miss the chance to take on his former club Barcelona having also delivered a positive test earlier this week.