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Fortuna Düsseldorf was the German team managed by Rösler. He took over the reins in 2011 and guided the club to promotion to the Bundesliga in his first season. Under his leadership, Fortuna Düsseldorf established themselves as a competitive force in the top flight, consistently finishing in the mid-table region. Rösler's success with the club earned him recognition as one of Germany's most promising young managers.