Real, Milan, Barca, United, Juve, and Liverpool. When one of the world's top 6 clubs come calling, what do you do?
It depends on how far he thinks he can take this Dortmund team. No doubt there on the verge of something special, and he might want to honor his contract and see what the limits of that team actually are.
Liverpool would be an interesting proposition though, because their ceiling is much higher. Were Dortmund not in a worse position than we are now when Klopp took over there?
I don't think he's coming, but you have to ask yourself the question at least.