The Brazilians return to Loftus Versfeld with a 1-0 lead from their away victory in Tunis on Sunday, thanks to Colombian forward Brayan Leon’s strike.
With the decider confirmed as a sold-out encounter, Cardoso emphasised that his team cannot afford to be complacent against the four-time African champions.
"Our thoughts have nothing to do with what we did in the previous [leg], it's a door that we closed and we look at this match as one that we want to play to win," said Cardoso.
"We want to be a strong team, we want to be very capable and to face it with the maximum sense of producing a result that has to be taken seriously in terms of approach.
"There's no way to relate to a moment like this than that, and it's also our usual way of playing so we cannot face the game in any other sense.
"We know very well what we have had, we know very well the respect we have for the team on the other side, but we also have a lot of respect for ourselves also – and that's what we really need to show on the pitch.
"We understand that this game will have different moments that we need to be very strong to deal with, knowing that we play in a context that is more familiar for us than the one in Tunis."
The Portuguese tactician also suggested he would not rule out tweaking how Sundowns set up now that they are playing in front of their fans.
"All strategies are right or wrong based on the result, and sometimes you think they were okay but because you got the result it doesn't mean that really the way you did things were correct," he added.
"Usually in football we have the tendency to say everything goes okay when there's a [positive] result, because people most of the time don't have the capacity to go deep in the analysis and they just look at the results, thinking everything was right.
"I think the match we played in Tunisia was not perfect for both teams, but for sure both team will try to make a better approach – that's usually what happens with good coaches and good teams."