Fink has been beaten three times by Bremen since taking charge of Hamburg, but he wants that to change at the HSV Arena and he is telling his players how important the 98th meeting between the two sides is.
"All of my players know what this game against Bremen means to our fans and the whole region," he said.
"Werder are going to be up for it, but we've got to show that we are even more motivated."
Hamburg have a three-point advantage over their rivals, who were beaten 5-0 by Borussia Dortmund a week ago.
Fink does not expect that result to help his side, though, saying: "You never can tell how a team will react to such a result.
"So we've got to learn to be alert from the beginning and that is what we want to prove tomorrow."
Fink is without the injured Michael Mancienne for the next month and this gives Jeffrey Bruma the chance to stake his claim for a regular starting berth.
On the other hand, the Hamburg coach is spoilt for choice in attack with in-form Artjoms Rudnevs, Heung-Min Son, Maximilian Beister and Marcus Berg all vying for two places.
The latter pair are likely to be on the bench, but Fink said they are "both in top form" and able to make a difference when called upon.
"That makes it a comfortable situation for me as a coach," he added.
The Bremen training pitch has not been such a comfortable zone for their players this week, but their coach Thomas Schaaf has paid tribute to their work ethic after such a crushing defeat.
"We have really worked hard," he said. "You could see them really putting everything into it.
"I am sure the team will not just accept the situation as it is without trying to change it.
"We have seen the reaction and now the question is how we can do better in our next game."
Aaron Hunt and Marko Arnautovic are slight doubts due to viruses, but Schaaf is optimistic that both will be able to line up in Hamburg.