Atletico travel to the Bernabeu for the first leg on Wednesday looking to make it three consecutive wins over Los Blancos in all competitions.
However, Miranda has put the pressure on Real Madrid, who he believes are the favourites for the cup clash.
"Not much has changed. They're still very strong and still the favourites. But we are a strong team too, brave and hard to beat. We're raring to go," he told AS.
"We know the Santiago Bernabeu will be a hostile environment, like playing at San Mames. But we won't be intimidated. We have shown already we can withstand that kind of pressure."
Atletico won 1-0 in the Bernabeu earlier this season in La Liga.