The Yellow Submarine remain fourth in the Primera Division after despatching Miroslav Djukic's side and now have the chance to put daylight between themselves and another European rival.
"We are playing at home and we hope we aren't still caught up in the euphoria from Sunday," Marcelino told a press conference.
"The game demands the same intensity and plan. If we are able to distinguish this game from the last and not be content with just winning that game, we will have taken the first step towards victory.
"If we drop our guard, we'll cause ourselves problems. The same thing that happened in Bilbao (when Villarreal were beaten 2-0 by Athletic) will happen to us, because this is a very even league."
Getafe had strung together four consecutive wins before their fine run came to an end with a narrow defeat at home to Athletic Bilbao.
As a result, Marcelino believes Luis Garcia's side may be extra-motivated when they arrive at El Madrigal.
He said: "Getafe didn't start the season well, but have managed to straighten themselves out in the last six or seven games. They've just had an unfair defeat and they will come here with hope and with the intention of winning."
Despite their opponents strengths, Marcelino is confident of his side's chances of victory, which would put seven points between Villarreal and Getafe.
"This is a chance to open up a gap and we know it, we are at home and against a team who for now are our direct rivals," he added.
"If we can forget the euphoria from Sunday and focus on what we have to do, we know we've got a good chance of keeping up this run."
Garcia will have a full squad to choose from, and while Marcelino has no fresh injury concerns, he admitted he may change his team around to give a rest to some players, such as Bruno Soriano, who picked up a knock against Valencia, and Cani, who has had stomach problems.