Ireland v Argentina:Before this competition began, eyes turned to Gordon D'Arcy whenever the word game breaker was mentioned. The Irish system does not roll game breakers off the rugby assembly line with great regularity but along with Brian O'Driscoll and Geordan Murphy, D'Arcy's name sat comfortably.

Why there has been little evidence of this to date has been one of those mysteries that may go down in history as part of the great rugby malaise of 2007, ranked up there with Saipan and the Great Famine.

D'Arcy is aware of it. He is aware of his significance against Argentina and aware that so far he has not been able to bring to the party those things the team has taken for granted over the years. In tandem, he will be playing opposite his Leinster team-mate and a player who, despite the occasional rush of blood, is carving out quite a reputation for himself in this World Cup, Felipe Contepomi.

The positive side of it is that while D'Arcy knows Contepomi's strengths, he knows his weaknesses too. But to exploit that he must first return to a game that people recognise as being typical of the Leinster centre.

"I don't know how you would judge my form," he says. "I suppose you can judge it on the Six Nations and I'm not making clean breaks. I'm not getting the yards that I normally do. I don't know where that is coming from. Is it coming from defence?

"It just doesn't seem to be clicking for me or us at the moment. I just need to really pull one out of the bag this weekend."

Everyone is thinking the same. But scoring four tries against a team that has traditionally troubled Ireland and often beaten them seems remote if not delusional. Argentina defeated Ireland twice this year, albeit, with front line Irish players missing. In 2004 Ireland won 21-19 at Lansdowne Road and the year before that earned a 16-15 win in Australia. In 2002 the score when the teams met again in Lansdowne Road fell 16-7 to Ireland. But current form tells more.

In this World Cup Ireland's try scoring average per match is 2.3, while Argentina's is 4.7. Ireland's average points scoring per match is 16.3 while Contepomi and his gauchos are up at 37.7. "It's going to be difficult enough having to beat Argentina without having the added pressure of needing to score four tries," says D'Arcy.

"For us, the first thing is to win the match. One of the boys put it pretty well yesterday - we are going to get two scoring opportunities in each half and we have to take them.

"The danger is that you go out and try to score four tries from the word go and then end up losing the game. That is not an option. The way you beat Argentina is you put them through phases and you take your scoring opportunities when they come. They have got a very hard and physical defence. You need to keep turning them around, putting them through phases and then they start getting a little bit narrow.

"That's when you have got to take your chances out wide but if you go out straight away to try and go through or around them they are very solid off first phase defence."

For D'Arcy, like O'Driscoll and several other Ireland players, the game could be defining and could mark a bleak or inspirational moment in their careers. The line speed, the sharp passing, the yardage making with which D'Arcy is so often associated, has vanished. Somewhat, ironically, he has to now find it against a team that is playing better than ever.

"The Argentinian defence hasn't really changed, it has always been good. In previous years what they have probably lacked is being a little more clinical in attack but they have that now. (Juan Martín) Hernández coming in at number 10 has brought another dimension to their game," he says.

"They are just very, very aggressive. They have a lot of line speed and come up in your face very quickly. With that, if you make a bust you can get in behind them very quickly. That's what we will look for this weekend - when they get that line-speed to get some evasion and to get behind the game-line. Once you get in behind them you have to be clinical with the passes because they scramble in behind very quickly as well.

"The main thing is, once we make a bust and get in behind them, that we don't panic and are clinical and put the ball through the phases or just put it over the line."

Pulling rabbits out of hats has been his forte before. Now more than ever D'Arcy must think like a game breaker.