Dunga's men were 2-0 winners over Argentina in Beijing on Saturday, Diego Tardelli scoring a brace for the World Cup semi-finalists.
The World Cup hosts have not conceded in three matches since shipping 10 goals in their final two matches of the showpiece tournament.
And Dunga said he was wary of making too many changes for the clash in Singapore, as he looked to build on the stability garnered from their three-match winning streak.
"I want to use all the possible replacements, which are six, especially because the players had to go through a very long journey to China and pollution conditions were very bad," the 50-year-old said.
"So they are very tired because of that, so I really intend to use all the replacements which are possible to be used in this match.
"I will first talk to the players to see the level of their tiredness, if they are ready then I'm not going to change it.
"We have now five new players in the line-up and they have played together for the fourth match.
"In my vision there is no point to be changing all the time, to be replacing players because I need to allow them to create a certain trust, to create a certain confidence so that they can play as a team."
Dunga, a former international of 91 caps for Brazil, said he could not compare the Japan team of 2014 to one he would have faced in his career between 1987 and 1998.
"I played against Japan many years ago but I cannot compare them to nowadays because at that time Japan had no experience in terms of international matches and today the Japanese team has improved a lot," he said.
"So it's a totally different situation where they have very good players that are playing in other leagues around the world."
