Van Marwijk's team lost 3-0 at home to Schalke 04 on Sunday, which has kept them in the relegation playoff spot in the Bundesliga after 18 games played.
"[The defeat] is all the more disappointing after the hard work we've put in these past three weeks," he told Bundesliga.com.
"I hope the players are aware of that now. Something has to change in their minds. We're playing just for our survival now.
"If everyone knows what we're fighting for, we'll get the points we need. After all, will still have enough matches left. I'm expecting a response from my players against Hoffenheim."
Nuremberg, in 17th, are just two points behind Hamburg.