The Mattress Makers were defeated 2-1 by Los Blancos in the first leg, but the Argentine tactician remains optimistic that they can overcome their bitter rivals at home.
"I believe in my players, I trust this squad," Simeone told the media on Tuesday.
"I absolutely understand the heart they have and I have no doubt that we will be looking to stay in the Champions League. Our objective is to play in the final.
"Football has different scenarios that happen during the game. We will go through difficult moments... The coolness, clarity and quality of the footballers will decide. The game is going to go that way.
"Our people will push us, but the reality is what happens on the pitch. We're not going to win just because of what happens in the stands. We have to play a great game."