Union Berlin are enjoying another superb season challenging for European football through the Bundesliga but coach Urs Fischer has admitted reaching the German Cup final would still be a shock. “Sensation would come close,” he said Monday as his side began preparing for Wednesday’s semi-final away to RB Leipzig. “For us it is a highlight game.” Union beat Eintracht Frankfurt 2-0 at the weekend in a strong performance built on the opening 45 minutes. “In Leipzig you have to play over 90 like we did in the first half,” he said. “We need an optimal game to cause a surprise there.” Union are sixth…