The League of Wales part-timers moved their Uefa Cup qualifying round tie with Celtic to Cardiff in a bid to maximise the gate receipts because of the limited capacity of their own Hafod Road venue. But their manager, Tony Willcox, was fearful of Celtic being given too much room to play because of Ninian Park's larger playing surface.
He explained: "Our own pitch is a narrow one so we want to make sure it's the same size or smaller tomorrow. At the very least that should give my lads less running around to do.
"The way Celtic pass and move the ball means it would have been tough for us otherwise. It's really all about preparing professionally, in the same way that rather than turn up in cars, we'll be staying in a hotel tonight."
Willcox admits that tactically his options are heavily restricted by the need to keep the score down and maintain a degree of respectability over the two legs in Europe.
He added: "We know the style of football Celtic like to play, but stopping it is another matter. We're going to have to put nine men behind the ball to try and stop them.
"Celtic's system at times sees them playing with just two defenders so in that respect they take a chance, but clearly they've got enough quality to get away with it against us."
Cwmbran have experience in their ranks with the former Welsh international defender Mark Aizlewood, but will be without striker Matthew Davis, their leading scorer last term.
With around 10,000 tickets already taken, Cwmbran remain optimistic the game could yet be a near-14,000 sell-out.
St Johnstone face VPS Vaasa in Finland tonight while Kilmarnock are in Iceland, playing KR Reykjavik. KR, who are three points clear in their domestic league with four games left, will field the former Aberdeen defender David Winnie.
The Kilmarnock captain, Kevin McGowne, said: "It used to be that Scottish teams would expect to win easily in places like Iceland. But that time has long gone. We have to respect KR because of their record and I am expecting a very tough game."