Hannover and Eintracht Braunschweig have both appealed for order on the eve of one of the most sensitive local derbies in German football.
Not since 1976 have the two Lower Saxony neighbours met, and the fear is all of the pent-up sentiments will be unleashed in and around the HDI-Arena this weekend.
Already, the German Football Association has accepted a request from hosts Hannover for the game not to be played on Saturday November 9, the anniversary of the suicide of Robert Enke.
They feared visiting fans would disrespect the occasion and only fuel further animosity.
Meanwhile, Hannover players wrote an open letter appealing to their fans to be sporting and enjoy the occasion while the coaches of both teams, Mirko Slomka and Torsten Lieberknecht, have featured in radio messages calling for calm.
Nevertheless, the security services are on high alert after Braunschweig fans released a pig wearing a Hannover scarf in the Lower Saxony capital.
``I don't want to deprive anybody of the hope that this will be a peaceful derby, but there is a particular risk,'' said the head of the local police force Guidon von Cyrson.
``Schalke against Dortmund is peanuts in comparison.''
Getting back to the sporting aspect, both clubs are keen on the points to make sure their fans go home the happier.
``Torsten Lieberknecht and I both desperately want to win this game with our teams,'' said Hannover coach Slomka on the Braunschweig website.
``Rivalry is fantastic, when it remains peaceful. You can feel that people in Hanover and the region are only thinking about this game.
``I saw how intense Schalke's rivalry with Dortmund was when I was coach there. Football fascinates people and anybody who understands how important football is and how important a club is to their fans, then they will understand what emotions are attached to a derby.''
Hannover captain Steven Cherundolo returned to training this week, although the USA international will not figure on Friday night, nor will Salif Sane or Marcelo, who are both suspended.
Lieberknecht has his full squad available for selection, however, and his side will be out to build on a surprise 1-0 win over Bayer Leverkusen last weekend.