Bayern Munich coach Julian Nagelsmann has endured his toughest week in charge of the Bundesliga leaders and Sunday’s home game against bottom side Greuther Fürth will suddenly look trickier than it might have been. Last weekend’s chastening 4-2 defeat at another promoted side Bochum meant Bayern’s advantage at the top was cut to six points by Borussia Dortmund’s 3-0 win at Union Berlin. The Bavarians wanted to prove Bochum was just an isolated aberration in their Champions League last-16 first leg at Red Bull Salzburg on Wednesday – but instead limped to a 1-1 draw with Kingsley Coman netting …