Police are braced for trouble when Leipzig returns to Borussia Dortmund in the Bundesliga on Saturday for the first time since violent scenes overshadowed their game last season.
Dortmund was fined and forced to close its 24,454-capacity south stand for one game following Leipzig's previous visit on Feb. 4, when some of its fans were attacked with stones and bottles, police officers were injured, and visiting players and officials were confronted with derogatory chants and banners in the stadium. Police opened 214 cases, leading to criminal proceedings in 168.
While not directly promoting violence, one Dortmund fan group has called on its members to again make their opposition to Leipzig known.
''In the Westfalenstadion and on the south stand, the same measures apply as last season,'' the Suedtribuene Dortmund fan group writes in an open letter to its members. ''Let us show what football is to us! Let us show that no money in the world can buy fanaticism, loyalty and a free and mature fan culture!''
Founded in 2009, Leipzig is unpopular among rival fans due to its youth and rapid progress made possible with backing from energy drinks manufacturer Red Bull through its co-founder Dietrich Mateschitz. The 73-year-old Austrian billionaire bought a local fifth-tier team, SSV Markranstaedt, rebranded it with his company's livery, and financed its steady promotion from the lower leagues to the Bundesliga and Champions League.
More than twice as many Dortmund police as usual will be on duty at the game.
''Our concept is to protect football fans from Dortmund and Leipzig from being harassed and attacked by violent offenders and criminals who don't deserve the title 'fan.' We will prosecute criminals by all means and with great effort,'' police chief Gregor Lange says.
Dortmund, which leads the Bundesliga after its best-ever start to the league, is hoping off-field issues do not distract the players from the game.
New coach Peter Bosz has led the side to 19 points from a possible 21, with a goal difference of plus-19 from seven games. But the Dutchman has warned that ''the mood can change quickly, so we have to keep working well.''
Leipzig has not enjoyed the same smooth start that took it on a 13-game unbeaten run in its maiden Bundesliga season, but Ralph Hasenhuettl's side appears to be finding consistency again after back-to-back wins over Eintracht Frankfurt and Cologne.
Leipzig will be boosted by the return of influential midfielder Naby Keita after his three-game suspension for a high challenge on Borussia Moenchengladbach's Christoph Kramer.
Germany striker Timo Werner could also make his return after training again this week. Werner hasn't played since Sept. 26 when he went off with a neck injury in the Champions League defeat at Besiktas.
Hasenhuettl said he would decide on Werner's participation at the end of the week.
Dortmund has not been beaten at the Westfalenstadion in the Bundesliga since April 4, 2015, a 1-0 defeat to Bayern Munich, and can stretch its 41-game record.
''Dortmund is rightly at the top and the best team in Germany at the moment,'' Leipzig midfielder Diego Demme says. ''But we can still get points there when we go to our limit.''