Celtic have confirmed they have suspended matchday ticket sales for the Europa League clash with Ferencvaros.
The club will become the first in Scotland to enforce new proof of vaccination on Tuesday afternoon as the so-called Scottish Government "grace period" comes to an end.
According to new Holyrood rules, anyone attending any event with a capacity of 10,000 or more must have had both doses of a Covid vaccine.
Ange Postecoglou's side are searching for their first points in Group G as face the Hungarians in Glasgow.
The game is a bizarre 3.30pm kick-off, owing to the COP26 Climate Conference taking place in the city.
The club have now urged fans to pre-book tickets by purchasing online amid the new protocols.
A Celtic statement read: "Owing to the introduction of the vaccine status certificate checks we have had to suspend all ticket sales on the day of the match for the Ferencvarosi TC fixture for operational reasons, to ensure the smooth implementation of these checks.
"This is expected to be a temporary measure. However, for any supporters looking to secure tickets for the game, you must now do so before 5pm on Monday, October 18.
"Tickets are now only available online, for Print at Home, and must be secured before this deadline to ensure entry to the stadium on Tuesday.
"There will be no options to buy online or from the Ticket Office on the matchday.
"We need every voice behind the team as they set out to claim their first points in Group G!"
Celtic have told fans they will accept three different forms of certification that can be provided to gain entry to Celtic Park.
Supporters can bring a printed out copy of their vaccine certificate, show a digital copy such as a PDF from their phone screen, or download the NHS Scotland Covid Check app — though many punters heading to games in recent weeks have complained the latter will not recognise their details.
