La Roja, the defending champions, were humiliated 5-1 by the Netherlands in their tournament opener, prompting questions as to whether the side needs an overhaul.
Fabregas, however, believes a familiar-looking Spanish outfit can post a response at the Maracana.
"The boss will have his ideas about what he has to change and what he will leave the same, but I don't think there will be a huge amount of changes because I think this side has shown how good it is," Fabregas told Movistar.
"We are positive, even though it has been hard. I see the side fully focused on what they have to do, training well, with the right mentality. We have to win and get the three points, which are vital."
The new Chelsea signing added: "It's up to us, we have to dominate the match. We know there will be times when we will have to resist and when we have chances, we will have to take them.
"The most important thing is to win, and then if we can score more than one goal, better. Then we'll have to play Australia."