Humphreys will start for Ireland

Irish coach Eddie O'Sullivan has named a full-strength side to face Argentina in Adelaide on Sunday.

O'Sullivan has opted for power in the pack, while David Humphreys will return at fly-half.

Humphreys played in Ireland's opening match and scored 18 points in the 45-17 victory over Romania.

Ireland's second-choice stand-off Ronan O'Gara kicked seven conversions in a 10-try, 64-7 demolition of Namibia in Sydney last Sunday.

We've gone for some physicality and bulk in the back row Ireland coach Eddie O'Sullivan

"There was a huge amount of debate about that," said O'Sullivan of the battle for the number 10 jersey.

"At the moment David is in the driving seat, just by the skin of his teeth really, but over the two games it could have gone either way."

In the pack, Munster's Alan Quinlan will start at openside flanker with Victor Costello at number eight.

Quinlan gets the nod ahead of Keith Gleeson, who is not even on the bench, while Costello will play instead of Eric Miller.

"The kind of game we're playing against Argentina is a pretty physical, close-quarter encounter, which it always is, so we've gone for some physicality and bulk in the back row," said O'Sullivan.

"It's a reflection of the team we're playing and the type of game we need to play."

O'Sullivan's side play Australia in Melbourne on 1 November in the probable showdown to win the group.

Argentina upset Ireland in the 1999 World Cup, beating them 28-24 in the quarter-final playoffs, meaning the Irish had to qualify for this tournament.

The hosts meet minnows Namibia on Saturday.