O'Driscoll urges the faithful to believe in Wallabies' fallibility

Enough of the craic, it is time for the Irish to get serious. Such a chance to topple a southern-hemisphere giant will rarely present itself in a more obvious form than the one put before them today. Australia arrive at Lansdowne Road with their bones bruised after a gruelling encounter in Argentina seven days ago and their energy levels battered after such a punishing travelling schedule coming on the back of a nine-week close season.

In contrast Ireland have never been in as good a shape for an autumn international. Two World Cup qualifiers against Russia and Georgia and a run-out against Romania in the past two months have sharpened the skills as well as the appetite and led Eddie Jones, the Wallabies coach, to declare Ireland "the best prepared team in the world at the moment".

But Eddie O'Sullivan, the Ireland coach, has been here before. Indeed, his side have had southern hemisphere teams on the rack in his short tenure and failed to turn the handle, most notably against New Zealand in Auckland in June. "In the last two years we've had opportunities to do something special and we have let them slip," O'Sullivan said yesterday. "We have learnt from these and the key issue will be if we believe in ourselves. If the opportunity does arise against Australia – and we will have to make it arise; it won't happen by just wanting it – we will see if we have made that crucial step."

Leading the way will be their new captain, Brian O'Driscoll, attempting to fill those unfillable boots of the injured Keith Wood. "We are without our spiritual leader and that will be another big test for us," O'Sullivan said, but in O'Driscoll at least he has a man, albeit a young one, who knows what it is like to beat the world champions.

The Lions' first Test win last year is still fresh in the memory of the 23-year-old centre. "I am the only one on the team to have beaten them, and I've been trying to get this over to the team all week: that Australia are just men are they are fallible," he said.

Most of this fallibility rests on the inexperienced shoulders of the hooker, Adam Freier, and the wing Wendell Sailor. The latter's battle with the equally combative Shane Horgan should be one of the highlights of the afternoon. But with the rains arriving here in Dublin yesterday to drown out the possibility of an expansive game the definitive contest will be between the packs. And although the experience of Owen Finegan is probably wasted in the second row, with the power of the front five allied to the ball-carrying mayhem likely to be wreaked by Toutai Kefu and George Smith as well as the aerial ability of Matt Cockbain, the world champions may just hold the edge. It will be vital for the home side that Malcolm O'Kelly has a good day at the line-out.

At half-backs there should be no contest, with the ACT pairing of George Gregan and Stephen Larkham without peer in the world. That said, if the Munster partnership of Peter Stringer and Ronan O'Gara can make the most of whatever ball comes their way then outside the massive influence of O'Driscoll, they may just swing things Ireland's way. They will find little given by the Australian backs, however, especially with Stirling Mortlock playing in his favoured role of outside-centre and Matt Burke doing likewise at full-back.

It is this ability to cover injuries anywhere from within a multi-skilled squad that so impresses O'Sullivan and why he believes the visitors remain favourites to win today. "They have this incredible inter-changeability between positions and players – the team just never weakens. And every Australian side usually gets the job done without much fuss," he said.

At least one of the Wallabies will have plenty to fuss over come this evening. Gregan, the captain, will fly back to Australia straight after the game. He will arrive on Monday to be at his wife's side for the birth of their second child. Then he will jump back on the plane to rejoin his team-mates on Wednesday in readiness for the showdown with England next Saturday. "It should be fine with the time differences and everything." Mrs Gregan was not available for comment.