Borussia Dortmund were forced to apologise to their fans this week after mistakenly displaying a Bayern Munich fan choreography in their Winter Catalogue.
The catalogue, which was sent to all club members, contained an image of fans displaying the yellow and black colours of Dortmund with a banner reading "The colours of the best city". It was, however, a choreography organised and performed not by the famous Dortmunder Yellow Wall, but by FC Bayern fans. When the two clubs met in the DFB Pokal last season, the European Champions in waiting had taken the opportunity to remind their rivals that yellow and black also happen to be the official colours of the city of Munich.
BVB have released a swift apology, describing the debacle as a "mistake from an external employee" and asking the fans "to excuse this human error". It is certainly an embarrassing one, with the two clubs set to play each other for the first time in the league this season in two weeks time. The atmosphere ahead of the "Klassiker" is already becoming heated. Dortmund chief executive Hans-Joachim Watzke put the pressure on Germany coach Joachim Löw this week, telling Sport Bild that he expected Löw to "handle both Dortmund and Bayern players in the same way" during the international break.
After Dortmund's 2-1 defeat to VfL Wolfsburg last weekend, Bayern have the opportunity to pull seven points clear at the top of the Bundesliga should they win the crunch fixture.