The Rojiblancos caused a shock by beating Real 2-1 after extra time in the final of the Copa del Rey in May, a match played on Real's home ground the Estadio Bernabeu.
Diego Simeone's side have carried the momentum of that victory into the current campaign and go into Saturday night's derby with a two-point lead over Real after six Primera Division matches. Atletico hold a 100 per cent record and are only behind Barcelona in the early standings.
The cup final win and the league table suggest Atleti have no reason to feel any sense of inferiority to their more illustrious neighbours, and Courtois, on loan to the club from Chelsea, told Marca: "We have a great team, we know how to beat them. (Playing for the) three points is (like) another final.
"As a player, you never play for a draw, you always play to win.
"There are players here who are in good form and others who are not, but I think the team as a whole can maintain the level and the spirit is good."
Midfielder Mario Suarez is a doubt for Atletico after straining ligaments in his right knee during Tuesday night's win over Osasuna, while striker Adrian Lopez is expected to miss out due to a fractured cheekbone. Both players trained away from the main group on Thursday.
Real come into the derby after an unconvincing 2-1 win at Elche on Wednesday night, secured by an injury-time penalty from Cristiano Ronaldo which was awarded in highly dubious circumstances.
Coach Carlo Ancelotti admitted his team would need to make a major improvement against far tougher opposition in Atletico.
By the time the Madrid derby kicks off Barcelona could be five points clear of Real, as they travel south to take on Almeria.
Barca have scored an impressive 22 goals in six La Liga games, and face an Almeria side who have not recorded a league win so far.
The Catalan giants are under the microscope, with new coach Gerardo Martino coming in for criticism. The Argentinian's tactics have had a negative impact, critics say, on Barca's traditional style which is based on dominating possession.
Defender Gerard Pique was especially frustrated by the increased scrutiny, and told Barca TV: "We are the only team that wins 4-0, and people argue if we have had more or less possession. It is a statistic that should not be as important as the media makes out.
"At times we come up against opponents who we have to take the ball from and then become more horizontal in our play, with a bit more variation. Tata (Martino) wants to instil that in us and I welcome it."
The seventh round of matches kicks off with Valladolid hosting Malaga on Friday night, before Valencia take on Rayo Vallecano at the Mestalla and Real Sociedad host Sevilla on Saturday.
Osasuna face Levante in the early game on Sunday, with Elche travelling to Vigo to take on Celta, Espanyol hosting Getafe and Villarreal going to Seville to face Real Betis.
Granada host Athletic Bilbao in the Monday night match.