Dunga started his second stint as Brazil boss with a 1-0 victory over Colombia in Miami on Friday, stand-in captain Neymar's 83rd-minute winner proving decisive.
The 50-year-old has been encouraged by what he has seen from his new-look team so far, but stated there is much work to do to banish the memories of a 7-1 semi-final defeat to Germany in Brazil's home World Cup in July.
"I think we have to continue the work we've been doing," he said. "We have to guarantee some confidence for the the new players.
"To undo everything that has happened in the space of one game is difficult, so we have to understand the conditions of each player, work on their positions and give opportunities for the new ones to come through.
"In football, we have to be better every day, every game. The more we train and repeat the moves, the more they will become automatic.
"So tomorrow we're going to sit down and think about what has gone in the right direction, and what we need to work on. In this moment, we need to highlight the qualities, more than look for flaws."
Dunga's reign continues when Brazil challenge Ecuador at MetLife Stadium in New Jersey on Tuesday.
