The Australian said the players had learned a lot from their opening 27-10 loss to 14-man England in Marseilles and had spent all week in training focusing on the basics.
"We know the type of game we want to play, we don't want to change too much depending on the opponent," he told reporters after naming his Argentina team on Wednesday.
"We have to be disciplined in our organisation, in defence and attack. It may take 60, 70 minutes until the opportunity is there, but you have to take it when it comes.
"You don't have to do something magical, it's about playing our game disciplined and very aggressively."
Cheika made three changes to his starting team for the match.
The experienced Matias Moroni comes into the midfield for Lucio Cinti, Guido Petti plays in the second row instead of the injured Tomas Lavanini and Eduardo Bello replaces Francisco Gomez Kodela at tighthead prop.
Cheika has also added another back to his bench in the shape of fly-half Nicolas Sanchez after going with a 6-2 split against England.
Sanchez will win his 99th cap if he gets on to the field on Friday. His fellow 34-year-old Tomas Cubelli brings even more experience to the bench as cover for starting scrum-half Gonzalo Bertranou.
Pumas skipper Julian Montoya said the more experienced players were ready to embrace the pressure on the twice World Cup semi-finalists after their disappointing first outing.
"We know there will be pressure, we are training for this. It's where we want to be. Nobody forces us to be here, we do it with a lot of passion, with a lot of love for the shirt and for what we represent," he said.
"The older ones are there to absorb the pressure. Let the younger ones think about playing. We are ready to have a great game against Samoa."
Argentina team:
15-Juan Cruz Mallia, 14-Emiliano Boffelli, 13-Matias Moroni, 12-Santiago Chocobares, 11-Mateo Carreras, 10-Santiago Carreras, 9-Gonzalo Bertranou, 8-Juan Martin Gonzalez, 7-Marcos Kremer, 6-Pablo Matera, 5-Matias Alemanno, 4-Guido Petti, 3-Eduardo Bello, 2-Julian Montoya (captain), 1-Thomas Gallo
Replacements: 16-Augustin Creevy, 17-Mayco Vivas, 18-Francisco Gomez Kodela, 19-Pedro Rubiolo, 20-Rodrigo Bruni, 21-Tomas Cubelli, 22-Nicolas Sanchez, 23-Lucio Cinti