Their tiny Rheinpark stadium ground, surrounded by the snow-capped Swiss Alps, could stage the worst night in Wales' history should a team rated 151st in the world come up trumps.
Frick, Liechtenstein's greatest-ever player, was suspended from Saturday's disappointing 2-0 home defeat by Azerbaijan in a World Cup group four qualifier, but returns against the Welsh to add to his haul of 90 caps and 14 goals for a country with just a 34,000 population.
St Gallen striker Frick, one of the few full-time professionals in the Liechtenstein side, said: "If we do beat Wales, it will be the best win in our nation's history. The best at the moment was when we beat Iceland, but Wales are bigger than Iceland."
Frick's return is likely to be the only change made by coach Hans-Peter Zaugg from the starting line-up that lost to Azerbaijan.
Frick said: "It is a very difficult match for us because we are also missing a lot of players. I was suspended against Azerbaijan along with some others and it was a really bad result for us.
"We are aware that Wales are also suffering from a loss of players and that their captain Craig Bellamy is not here. We will have a stronger team on Wednesday so maybe it will give us the chance to take advantage.
"We also understand there is pressure on the Wales coach (John Toshack) and maybe that is also something that could work in our favour.
"But do not forget that we have had to go down to our under-21 team for players to bolster the senior team.
"We also find ourselves at the bottom of the group, which is disappointing. We know that if we can beat Wales we will get out of that position.
"We hear that Wales have many very young players, but then so are ours. Their players are with top clubs in England, so people must understand that difference.
"We have produced a good draw at home to Finland this season, and that has given us confidence."
Liechtenstein have wins against Luxembourg, Latvia and Azerbaijan to their name, plus draws with Portugal, Slovakia and the Republic of Ireland.
While England won both Euro 2004 qualifiers against them 2-0, while the recent draw at home to Finland impressed.
And Zaugg also sees a potential victory against Wales, saying: "We will do everything we can to win this game. If we defend well, play well, we know that young teams like Wales can make mistakes. We hope so."
Zaugg has Zurich midfielder Martin Buchel suspended, while defenders Michael Stocklasa and Franz-Josef Vogts are both injured.
Midfielder Michele Polverino is also a doubt with a muscle strain.