Despite Milito's stunning club form, he is considered an understudy to Gonzalo Higuain in Diego Armando Maradona's World Cup side.
"The Coach makes his choices and it is our job to be ready to give our contribution for Argentina," insisted El Principe.
"We played a good game today, although we made many mistakes in front of goal, but there is certainly time to improve," he said of the 1-0 win over Nigeria.
"I am happy and the important thing was to start with a victory. Now there are another two group games in front of us and we must give it our all."