Ireland coach Declan Kidney says the Welsh clubs' poor form in European club rugby this season will have no bearing on the countries' RBS Six Nations encounter on Saturday.
While Ireland will be represented by Munster and Ulster in this season's Heineken Cup quarter-finals, Welsh trio Cardiff Blues, the Scarlets and Ospreys all made pool stage exits and won just three games between them.
That form has helped make Ireland favourites to win in the Millennium Stadium but Kidney was in cautious mood ahead of a difficult first game of the tournament.
"European form has nothing to do with it," he said. "We are playing the Grand Slam champions in their own back yard. "It will be a real Test game, and that is the excitement and the challenge.
"It is a clean slate for everybody and seeing who gets out of the traps first at half-past-one tomorrow."
Despite Wales' preference for the roof to be closed, it will be open because the teams could not reach an agreement and such an arrangement may help Ireland, according to their captain Jamie Heaslip.
"I played here when the roof was closed in the (2011) Heineken Cup final," said Heaslip, who will skipper his country in a Six Nations match for the first time.
"It's pretty intense and pretty loud, and letting a bit of the noise escape out of the roof isn't necessarily a bad thing. It is pretty humid down on the pitch (when the roof is closed).
"Outside of Ireland it's probably my favourite ground to play in. It is a great crowd and a great atmosphere."