Argentina and Leinster star Felipe Contepomi believes securing a crucial bonus point against Namibia tomorrow is no foregone conclusion.
Ireland failed to secure a bonus point against Georgia and that has convinced Contepomi that the two group minnows are no pushovers.
"We have to win and be ambitious," he said. "Every match is a new story for us and if we are able to achieve what we want, then we have to get the bonus point.
"Against Georgia we learned it's never easy to get it and we felt better when we saw Ireland couldn't achieve it against Georgia.
He added: "Ireland's game with France is of no importance to us. All that matters is us qualifying in the first place. I don't mind about the others because I just worry for Argentina's colours."
Contepomi surrendered the outhalf duties to Stade Francais star Juan Martin Hernandez for the opening two games of the World Cup.
But Hernandez has been ruled out with a back injury until the final Pool D clash against Ireland a week on Sunday, forcing the reshuffle.
Contepomi, who will be winning his 55th cap tomorrow, is ready to shoulder the extra responsibility that comes at outhalf.
"When you play as a number 12, you don't have to worry to be the playmaker of the team. As a number 10 you take more decisions," he said.
"I have played many times as a fly-half for Leinster and for the national team alongside Agustin Pichot at scrum half."
Namibia prop Marius Visser is delighted to be back in the side after recovering from a knee injury - but is expecting a hard time containing the feared Pumas front row.
"For sure it has been a while since I played. I'm looking forward to it. It should be an awesome match against Argentina," he said.
"It will be a big challenge. So far it has not gone all our way in the scrum, so hopefully we can bring a change in our scrum.
"It will be very difficult, Argentina know how to scrum and it will be a big contest up front. But we'll have the Marseille crowd behind us and going for Namibia because Argentina are France's big rivals."
