Having fallen behind to a Tomas Pekhart header on 31 minutes, Dortmund did well to respond when Jakub Blasczczykowski equalised five minutes before half-time.
The game became increasingly combative and Klopp blames the officials for the sporadic nature of the play and indeed the stagnated outcome, though he does lend some credit to Nurnberg’s tactics.
“What was unacceptable was the refereeing performance," he told Spox. "It is so hard to play football when that happens. We have been the fairest team for three consecutive years and today we got more yellow cards than Nurnberg. Nobody wanted to play unfairly today, but there were free kicks for no reason."
He added in his post-match press conference: “The opposition made it very hard for us, playing in many one-on-one duels, man marking in order to take Mats [Hummels] and Marco [Reus] out of the game.”
BVB now sit in fourth in the Bundesliga after two games.