The Selecao were forced to come from behind against Peru in their first game of the tournament, with Neymar scoring the equaliser and then setting up an injury-time winner for Douglas Costa.
And Dunga feels his side must make sure their passing improves as they take on a Colombia side desperate to recover from a shock opening day defeat to Venezuela.
"We have to play better in a technical aspect," he told reporters. "We missed a lot of passes against Peru, which is normal for the first game as you are eager to get the win.
"Let's hone this, and let's hope it's a calmer match, with fewer fouls."
Despite Colombia's surprise loss, Dunga does not expect coach Jose Pekerman to make many changes to a starting XI which contained talents such as James Rodriguez, Radamel Falcao and Juan Cuadrado.
"I don't think they will make that many changes to their team over one match," he added. "There's pressure, yes, because if they don't win then everybody around football will think that everything's wrong with them.
"At this Copa America, matches will keep getting tougher. Colombia will come out more determined and focused after their debut result. It will be a complicated match, like every other in this competition."
The match will likely see Neymar line up against Juan Camilo Zuniga, the player who injured him in the quarter-final of the World Cup last year, ruling him out of the remainder of the competition, with his side then losing 7-1 to Germany in the next game.
However, Dunga does not believe the reunion of the two players will cause any problems and is sure that the Napoli player did not mean to hurt the Barcelona star.
"There are no concerns over Neymar," he said. "He has already played against Colombia in the United States since that incident.
"The way I see it, it was a harsh but normal duel. Zuniga lost his coordination. He couldn't stop, so he ended up fouling him. I always think no player goes into a tackle with a malicious thought; to try to take an opponent out of the match."