Andujar and Agustin Orion are behind Sergio Romero in the pecking order to be in goal for Alejandro Sabella's side.
And while many believe Romero will be untroubled in Argentina's second game in Group F against the Iranians, his understudies said it would be folly to underestimate Carlos Queiroz's men.
"If you see how the games were, it is clear that the level it is very similar except for Germany," Andujar said.
"All the other games were very close and we cannot underestimate any team.
"It is clear we are the favourites of the group and we are the favourites against Iran.
"But we have to show it on the pitch that with the names alone do not win the games.
"You can look what happened in the game Belgium game or even the Brazil game.
"We have to win to avoid any surprises later."
Andujar has 10 international caps to his name, seven more than fellow custodian Agustin Orion, who said, while he has not yet been involved on the pitch, he is hoping for a long stay in Brazil.
"I am playing in a World Cup which is the best for a player and all of us, not matter what our role is have to give the 100 per cent," Orion said.
"I hope Argentina will do it well and we could stay until the end. The training sessions are very good and we enjoy them a lot.
"We have three goalkeepers. It is truth that we are not playing a lot but we are trying to give as much as possible."
Orion added he agreed with Andujar that Argentina had to be focussed for their clash in Belo Horizonte on Saturday.
"I think as you can see in the games, you have to play all the games," Orion said.
"Obviously, with the role of favourite which everybody talked about - we have to show it on the pitch and hopefully, we could improve what we did the other day getting a good result, and I hope if we get the result we could pass through.
"But we have to admit that all the games have their difficulties and we have to know how to overcome it, and show it on the pitch."
