Atlético ended a 14-year run without a win against their city rivals with a 2-1 victory after extra-time in May.
Los Rojiblancos have kept that momentum going this season with another win over Real in their only meeting so far this season in La Liga back in September.
Atlético also became outright leaders in the league for the first time since their double-winning campaign in 1996 with a 4-0 victory over Real Sociedad on Sunday.
However, despite Atleti's recent upturn in fortunes against Real, captain Gabi is aware of the challenge that faces them to make it back to the final.
"It is another opportunity that we have earned ourselves, to play against one of the best teams in the world," he told the club's website.
"To play in the final two consecutive years is very difficult to achieve. What this team has achieved until now has been thanks to our sacrifice, courage and union in the dressing room and we will take those qualities into the semi-final."
Whilst Atlético are in the midst of a 23-game unbeaten run, Real themselves have been in fine form of late and are unbeaten in 21 games.
Carlo Ancelotti's men's 10-game winning streak was brought to an end on Sunday though as they could only manage a 1-1 draw away to Athletic Bilbao.
Recently crowned Ballon d'Or winner Cristiano Ronaldo was sent off in that match for lashing out at Carlos Gurpegi 15 minutes from time, but the Portuguese is set to be free to face Atlético and serve his suspension solely in La Liga.
Ancelotti should also have Gareth Bale at his disposal as the Welshman has returned to training with his teammates after missing the last two games due to a calf injury.
Barcelona are also in semi-final action on Wednesday as they host Real Sociedad.
The Catalans will be looking to put their first defeat at the Camp Nou in the league since April 2012 behind them as they were sensationally beaten 3-2 by Valencia on Saturday.
Brazilian forward Neymar has stepped up his recovery from an ankle injury, but is not expected to be fit in time to take any part in the game.
Otherwise, Barca boss Gerardo Martino has a fully-fit squad to choose from and is looking for a reaction from his side.
"When you suffer a defeat the next match is always an opportunity to vindicate yourself,"he said.
"We don't need to just play well to wipe away what happened against Valencia, but because these 90 minutes will be important for the second leg in San Sebastian."
Real Madrid v Atlético Madrid (1900 GMT), Barcelona v Real Sociedad (2100 GMT)