Sexton will face Aussies

Ulster No8 Chris Henry will win his first cap from the start in a side showing four changes to that which capitulated to the All Blacks.

Predictably, Paddy Wallace steps in for the injured Gordon D'Arcy and Niall Ronan edges out Leinster rookie teenager Rhys Ruddock, who could also earn his first cap from the bench.

Ireland U20 captain Ruddock will also be buoyed by Ireland's power-packed 53-23 win over Scotland in the 9th-10th place finish in Argentina yesterday, Leinster sensation Andrew Conway striking for a hat-trick of tries.

Mick O'Driscoll is listed in the second row after recovering from a back injury to partner Donncha O'Callaghan. Cian Healy, Sean Cronin and Tony Buckley will look to undermine a suspect Wallaby front row.

In the replacements, the admirable Ruddock and hooker Damien Varley, who made such an impression against the Maoris, are the other uncapped players in the match 22.

Ireland will have to combat the fearsome Rocky Elsom and co, with what could effectively be described as their Z-list backrow against Australia at Suncorp Stadium.

Backs coach Alan Gaffney said: "It's unbelievable. I've never seen anything like it. But we keep learning. I mean, (John) Muldoon stepped up to the plate, didn't he? And he would not have had that opportunity at the start of the year; he was down the pecking order."

In total there are eight backrow forwards ruled out of contention by injury or suspension, with David Wallace released from tour duty to attend the birth of his second child.

Ireland team manager Paul McNaughton saidd: "It was known (that he might have to go home). Obviously, it depended on when the baby was going to be born, but he felt that he should be there for the birth and his wife is expected to have the baby in the next couple of days."

Despite the litany of injuries, Gaffney remains confident Ireland can inflict a first away defeat on Australia since 1979. The concentration will be on keeping the ball and working the phases, as they did to claw back a 20-all draw in the November international at Croke Park and, again, in the second half against the All Blacks in New Plymouth.

"We've just got to go into the game and give it a crack. That's all we can do," he admitted.

"The more we keep the ball in hand, the more we keep them under pressure. Because I still think we have the ability of attacking them in midfield, as we did at Croke Park."

Wallabies coach Robbie Deans has made just two injury-enforced changes to what is also a depleted side, bringing in Adam Ashley-Cooper and Luke Burgess. Ashley-Cooper is promoted from the bench to the wing in place of the injured Digby Ioane and scrum-half Burgess returns for Will Genia, who is out with a broken hand.

Ireland: R Kearney; T Bowe, B O'Driscoll (capt), P Wallace, A Trimble; J Sexton, T O'Leary; C Healy, S Cronin, T Buckley, D O'Callaghan, M O'Driscoll, N Ronan, S Jennings, C Henry. Replacements: D Varley, T Court, D Tuohy, R Ruddock; E Reddan, R O'Gara, G Murphy.

Australia: J O'Connor; A Ashley-Cooper, R Horne, M Giteau, D Mitchell; Q Cooper, L Burgess; B Daley, S Faingaa, S Ma'afu, D Mumm, N Sharpe, R Elsom (capt), D Pocock, R Brown. Replacements: H Edmonds, J Slipper, M Chisholm, M Hodgson; J Valentine, B Barnes, K Beale.