But the German insists he's committed to BVB.
"I can turn them down straight away," he told Sky television after his side's dramatic German Cup semi-final victory over Greuther Furth on Tuesday night.
"I will not be moving there. But I do think it is cool that I am being named in the same breath as Mourinho and Guardiola.
"That is enough for me - that is already a personal triumph, but I am not available, sorry."