Speaking to Sky Germany after the game, Dortmund coach Nuri Sahin couldn't hide his disappointment at Can's dismissal.
"He should never do that. He knows that," Sahin told Sky Germany after the game.
"That was a game changer. The boys are on their last legs," he said, referring to Dortmund's current injury crisis.
He added that he thought his team had played a "decent game" before the red card.
Dortmund midfielder Julian Brandt echoed similar sentiments after the Black and Yellows' fourth consecutive away defeat in the Bundesliga.
"The early red card didn't help us. He knows he has to be a bit more careful. He's very angry about what he did," Brandt said, adding:
“But that's not why we conceded the three goals.”
After 10 games of the season, Dortmund are 10 points behind leaders Bayern Munich.
"We don't have to concern ourselves with Bayern Munich at the moment. We have other things to worry about," admitted sporting director Sebastian Kehl.
