The impenetrability of the Hannover Arena is Club Atlético de Madrid coach Diego Simeone's biggest fear as his side look to edge closer to the UEFA Europa League final, a short distance from where the Rojiblancos won the competition in 2010.
Hannover 96 have won five and drawn two of their seven home games in Europe, spanning two campaigns, and although they must overturn a 2-1 first-leg deficit to end Atlético's hopes of replicating their Hamburg success, Simeone says the quarter-final is far from over.
"The fans are very passionate about their football here and it's no coincidence that they have not lost at home for months," he said. "You just have to look at the Bundesliga to see how strong they are."
Indeed, Hannover's comfort within the confines of their stadium is not reserved for European competition. They are the only team unbeaten at home in the Bundesliga this season and Atlético playmaker Diego, formerly of SV Werder Bremen and VfL Wolfsburg, knows what lies in store on Thursday.
"The statistics speak volumes and, with their fans behind them, we know we are in for a tough game," he warned. "The best thing for us to do is to forget all about our advantage. We have to play intelligently and play to win, as we always do."
Hannover coach Mirko Slomka does not expect anything else. "I have seen them a lot and I don't think they've ever played defensively," he said. "They are without three important players [Arda Turan, Gabi and Juanfran through suspension], but Atlético can and will replace them sufficiently. Yet it does give us some advantage because we saw how important those three were in the first leg.
"Arda Turan gets forward a lot and caused Manuel Schmiedebach problems in the first leg. Gabi is an important central midfielder who maybe does not look so special at first glance, but he takes charge of matters and has a lot of experience."
How much of an edge Hannover could gain from their opponents' absentees is something Slomka could not quantify, however. "I may have been a maths teacher, but calculating percentages was never my subject."
History is somewhat easier to fathom, according to Hannover forward Didier Ya Konan, who said: "We can go into the history books tomorrow night and each and every one of us want to do so."
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