MILLENNIUM STADIUM, Cardiff -- Ireland head coach Joe Schmidt refused to blame the loss of key players for his side's World Cup quarterfinal exit to Argentina on Sunday.

Ireland were rocked by tournament-ending injuries to talismanic captain Paul O'Connell and Peter O'Mahony, before Jonathan Sexton was cruelly ruled out of the last eight clash at the Millennium Stadium on the eve of the game.

Following Argentina's impressive 43-20 victory at the Millennium Stadium, Schmidt hinted a lack of experience in his side may have influenced the outcome but stopped short of blaming defeat on his side's injury crisis.

"That's the nature of the game," Schmidt said during his post-match press conference in south Wales.

"I'm incredibly proud of the way our guys stood up and I know those players that weren't available are incredible proud of them as well. You have what you have and you do what you do -- those guys did what they did with an incredible amount of character.

"There were a lot of players who have never been in a match of that intensity. Hopefully that learning experience will offer something in the future. I can tell you the dressing room is very disappointed. It's difficult, but that's the nature of the game."

Two quick tries from Matias Moroni and Juan Imhoff gave Daniel Hourcade's men a commanding lead in the early exchanges, before Ireland worked their way back into the match.

Ian Madigan started after Jonathan Sexton was ruled out © Stu Forster/Getty Images

However, following missed Irish chances to tie the game at 23-23, Argentina took full advantage to effectively knock their opponents out of a World Cup for a third time.

"We expected them to start like that," Schmidt said. "We had a look at their first pool match and they did exactly the same against the All Blacks. We know the quality of both those teams so we knew it was going to be tough.

"They made the most of those two opportunities early in the game. Building that scoreboard pressure gave them a real lift in confidence and dented that of our group. We certainly weren't overawed by the occasion but it was a very big occasion for some of ours. It made it difficult with the intensity they started with.

"You can't afford to give a head start like that to such a good team. At 23-20, we worked an overlap in their 22 that we didn't quite get. That's probably a little lack of experience and that's a little frustrating.

"But once we were chasing the game, there was always the potential for them to get a couple of breakaway tries because they've got such gifted players. You tend to force things and over commit when you don't need to, you chance your arm in positions that you wouldn't otherwise. It either comes off for us or for them -- we didn't quite get the rub of the green."