Gracia led Almeria to promotion to the top flight last season before his contract ended, and takes over an Osasuna side beaten in all three games so far this season.
Midfielder Roberto Torres says he is impressed with what he has seen of the new coach.
"You can see how enthusiastic he is when he explains the coaching drills, it's as if he's another player," he told reporters, quoted in the Diario de Navarra.
"It's nice to see someone work with so much enthusiasm, it's contagious and in the end you feel the same way."
And he said Gracia's arrival has unleashed a positve atmosphere in the squad.
"We are all starting from scratch, we are excited about seeing the first squad and team sheet and we all have renewed hope. After such a bad last year, it's a breath of fresh air."
Getafe have had a similarly poor start to the campaign, taking just one point so far.
Torres added: "It will be difficult, they are down in the dumps too, they have just one point and also have internal problems.
"There'll be difficult moments in the game which we'll have to battle through, but we need to give our fans a lift. We have to go out and take them on."
Osasuna will be without midfielder Miguel de las Cuevas, defenders Jon Echaide and Miguel Flano, plus forward Juan Francisco Martinez Modesto 'Nino', who are all injured.
Getafe on the other hand are without midfielders Jaime Gavilan and Medhi Lacen.
Midfielder Pablo Sarabia said the Madrid side are optimistic about the game and the impact it could have.
He told reporters: "Every game can be a turning point, depending on how you look at it. We are going to give everything on Sunday and give it our best shot, and of course, go for the three points."