Hamburg will travel south to Bavaria for the second leg of the Bundesliga's promotion-relegation play-off hoping to maintain their record of having played every season in Germany's top tier.
The first leg on Thursday finished 0-0 in Hamburg and Kramer wants Greuther's fans to cheer his team into the Bundesliga.
"I think our fans... will whip us forward. I hope I will not be the only one after the game, which is hoarse," the 42-year-old told Greuther's website on Friday.
Greuther finished third in the 2.Bundesliga and must overcome Hamburg in a two-legged play-off to reach Germany's top flight.
Hamburg are the only club to have played every season of the Bundesliga but are 90 minutes away from relegation, although their coach Mirko Slomka said his team's away form makes them a threat in the second leg.
Slomka's side have scored in their past four away games in the Bundesliga, although they lost all four.
A score draw would be enough for Hamburg to avoid relegation.
"We are always good for a goal away from home so the mood in the changing rooms is full of fight and determination," Slomka said.
"Sunday promises to be very exciting."
The history of the two clubs could scarcely be more different with Greuther having played their maiden Bundesliga season in 2012-13.
Greuther's sporting director Rouven Schroder challenged the Bavaria-based side to produce an even better performance in the second leg.
"We need an even better game," Schroder said.
"Faith has not decreased. The goal is great but close."
