Real's start to the new season has been sluggish, with a draw against Valencia last weekend followed by defeat to Barcelona in the first leg of the Supercopa.
Getafe are also looking to improve after a 2-1 loss to Sevilla in their La Liga opener, and Garcia knows they will have to do much better if they are to shut out their local rivals on Sunday.
"What I care about is my team, demonstrating that desire, that hope, that faith and that enjoyment of playing against the big teams," he told a press conference.
"We will try not to change things too much. We will try to be a strong team and aggressive.
"No one expects us to win, but we will try to beat Real Madrid. It won't make much difference to the standings but we want to win it for the team and for our fans.
"We will face one of the two best teams in the world and these things require a lot of concentration. To win we have to put on a performance and we can do that.
"I don't think the Supercopa will affect them but they will be on the alert after the draw with Valencia, because to win the league you have to be close to 100 points and if you lose one, you don't get it back."
Madrid defender Sergio Ramos has also told his team-mates to forget about the Barca loss and concentrate solely on Sunday's trip to the Coliseum Alfonso Perez.
Jose Mourinho's men were edged out 3-2 at the Nou Camp, but Ramos said on www.realmadrid.com: "We did a good job and the tie is still open.
"Now we have to unwind, relax and think about the best way to beat Getafe.
"The most important thing now is the Getafe match. It is not an easy stadium to play at and it will be another difficult clash.
"Things are always exciting at the start of the season and we now have to rest up well for Sunday."
Madrid will be without midfielder Nuri Sahin, who will undergo a medical in Liverpool on Saturday after agreeing a season-long loan deal with the Anfield club.