Pumas coach Marcelo Loffreda has confirmed Agustin Pichot and Gonzalo Quesada will be the Argentina half-backs for their key match against Ireland on Sunday.

Felipe Contepomi, who was the fly half in the opening match against Australia, will move to the centre position.

Loffreda decided to maintain most of the starting line-up from the match against the Wallabies after using a lot of the reserves against Namibia and Romania, but with some key modifications.

In addition to moving Contepomi, whose brother Manuel had been the centre in the first match, there will be four other changes.

In the front row, Federico Mendez and Mauricio Reggiardo will replace Mario Ledesma and Omar Hasan. Lock Rimas Alvarez takes Patricio Albacete's place and, in the back row, Lucas Ostiglia replaces Santiago Phelan.

The Argentina camp recognise the importance of getting things right on Sunday.

"It's the most important match. It's all or nothing. It's winning and advance to quarter-finals, as we did in 1999, or losing and return to Argentina with our hands empty," said Stade Francais fullback Ignacio Corleto.

"I imagine the last minutes of the match like those ones in Lens in 1999.

"Not winning by 10 points, but by a small margin. They say they're better than in that time, but we too."

The Argentinian team took part in their usual training session on Friday in the Oval stadium, where the match will be held, although Pichot did not participate due to having a temperature.

Argentina team:

I Corleto; J Piossek, J Orengo, F Contepomi, D Albanese; G Quesada, A Pichot (capt); R Grau, F Mendez, M Reggiardo, I Fernandez Lobbe, R Alvarez, L Ostiglia, R Martin, G Longo