O'Sullivan - ready for physical clash. (Getty Images)

By Gareth Duggan, PA Sport, Adelaide

Ireland coach Eddie O'Sullivan has picked his three most physically-imposing back rowers in a bid to win the "hand-to-hand combat" of their World Cup pool match against Argentina in Adelaide on Sunday.

O'Sullivan was quite clear as he described the likely environment of fierce tackling and scrummaging, admitting the loose forwards had been selected specifically for their ability to compete physically.

The result is that Victor Costello will start at number eight, with Alan Quinlan at openside and Simon Easterby on the blindside.

As well as making key decisions in the back row, O'Sullivan again opted for David Humphreys at fly-half ahead of Ronan O'Gara, despite the latter's superb showing against Namibia.

But any match against Argentina inevitably demands a neutralisation of their aggressive forwards and the coach is under no illusions about what awaits his team in the tranquil surrounds of the Adelaide Oval.

"It will be a bruiser, and it will be hand to hand combat and it won't be for the faint-hearted," said O'Sullivan, confirming that the approach to selection was no late brainstorm.

"Argentina is something we discussed a long time back among ourselves, and we always felt that this game would be different and we'd cut our cloth accordingly," he said.

"We are lucky with the players we do have in the back row - we can mix and match in that quarter."

The selections mean Miller is on the bench, while Gleeson will don a suit and tie to watch from the stands. Anthony Foley is injured and was not considered, but is expected to resume full training on Friday.

"The guy who probably feels hard done by, and rightly so, will be Eric Miller, who had a super game last week," said O'Sullivan.

"It's tight calls in these situations, which is a reflection on the quality of the players we have and Eric is on the bench for that reason," he said, while also offering soothing words for Gleeson.

"It's more to do with the make-up of the back row rather than Keith Gleeson and he's aware of that."

O'Sullivan admitted he had an embarrassment of riches when it came to the ever-prickly issue of selecting Humphreys or O'Gara.

"They're both men on top of their game, both of them are very capable players and it's such a shame I can only put one of them out there with the game we're playing.

"There's been a case before for playing them at first and second five-eighths, but I don't think that plays to the type of game we're playing or the patterns we run in attack or defence so that's not really an option."

Given that the match against Argentina has been Ireland's focus for months, players like Gleeson, Miller and O'Gara are certain to be disappointed but captain Keith Wood described their reactions as thoroughly professional.

"They've dealt with it very well. Eddie spoke this morning of the need for horses for courses and the fact that there will be changes dependent on the people that should play," said Wood, who will win his 56th cap in the match.

"Of course some guys are disappointed, you wouldn't want them to be happy or to take it in their stride - that's of no value," he said.

"You want guys to be pretty peeved that they're not playing because you need them to have an edge if they're called upon."

The rest of the team boasts the sort of consistency that has lifted Ireland to number four in the world rankings.

The backline is built around the brilliant running of centre Brian O'Driscoll and the pack constructed on Wood's broad and recently repaired shoulders.

O'Driscoll is partnered in the centre by Kevin Maggs, with Denis Hickie and Shane Horgan in the wings and Girvan Dempsey providing his unflappable presence at full-back. Peter Stringer is again at scrum-half.

Wood is joined in the front row by props Reggie Corrigan and John Hayes, with Paul O'Connell and Malcolm O'Kelly locking the scrum.

Ireland: G Dempsey (Leinster); S Horgan (Leinster), B O'Driscoll (Leinster), K Maggs (Bath), D Hickie (Leinster); D Humphreys (Ulster), P Stringer (Munster); R Corrigan (Leinster), K Wood (Munster), J Hayes (Munster), M O'Kelly (Leinster), P O'Connell (Munster), S Easterby (Llanelli), A Quinlan (Munster), V Costello (Leinster).

Replacements: S Byrne (Leinster), M Horan (Munster), D O'Callaghan (Munster), E Miller (Leinster), G Easterby (Rotherham), R O'Gara (Munster), J Kelly (Munster).