Gareth Thomas’s Wales side get their first real taste of the conditions they can expect at the RWC 07 when they meet Argentina under the closed roof at the ground tomorrow (Saturday).

The Invesco Perpetual Summer Series clash between Wales and the Pumas is a carbon copy of the opening match at RWC 1999, hosted by Wales.

On that occasion, however, tournament rules did not allow the new retractable roof at the stadium to be closed and Max Boyce had the privilege of ‘singing it open’ at the official opening ceremony.

“It was an emotional day for me and so impressive to watch the roof retract while I was singing to the heavens in front of a massive 75,000 strong crowd,” said Boyce.

“The Millennium Stadium is a magnificent place to perform, I’ve played lots of places over the years and with the roof shut it matches them all – although the acoustics are slightly better in the Sydney Opera house and there is less crowd participation!

“Even at part capacity this weekend the atmosphere is going to be electric. I try not to miss a match at home – and I even went to Argentina last year – its going to be tough for the boys to bounce back after the England game, but I’m backing them to do it.

“Something special happens in Wales when our rugby team wins and Alfie and his team have the capacity to put a smile on the face of the nation on Saturday and we all need to ensure we are in good voice to cheer them through.”

Thomas’s men will play both the Pumas and France the following weekend with the roof shut as they prepare to face Australia and Japan in next month’s Pool B clashes in similar circumstances on home soil in Cardiff.

RWC 07 organisers have decided that all four games at the Millennium Stadium – three Pool matches and a quarter-final – will be played with the roof closed to create the best possible playing and spectator environments and to ensure conditions are the same for all teams.

Wales played in sweltering conditions in their first warm-up match this month against England at Twickenham, when the temperature gauge on the sun-baked pitch rose to 86 degrees.

Since then, though, much of the UK has been rain soaked and the Met Office weather prediction for Saturday is 'cloudy with rain or heavy showers'.

But, over the next two weekends, Welsh fans will find a warm and dry welcome at the Millennium Stadium as they turn up to back their team to the World Cup.

“The roof will be closed for both games in the Invesco Perpetual Summer Series. That’s how it is going to be for our two matches at the stadium during the Rugby World Cup and so these games will give us the chance to get properly acclimatised,” said Wales Head Coach Gareth Jenkins.

“We obviously know the Millennium Stadium very well, but it does play differently with the roof closed. It can be a more intimidating place for teams to visit, especially when the Welsh fans are in good voice.

“Just as the players are preparing for the real thing next month, we hope the fans will be approaching the games in a similar fashion. Our fans can be our 16th player and we have to ensure they play their part.

“We are one of a few teams who are able to play our August matches at a Rugby World Cup venue and we would be silly not to take full advantage of that by matching the conditions as closely as possible.”

The first Rugby World Cup matches played under a roof were staged at the Telstra Dome in Melbourne, where Wales beat Canada in 2003.

Tickets are no longer available from Ticketmaster, but can be purchased in person from the ticket office at 98 St Mary Street in Cardiff, where collections will also be held, and the Cardiff Blues rugby club on Westgate Street right up to kick-off – they are priced at £30/£20 adult and £15/£10 concession.