The Telegraph says he is understood to have laid out demanding terms for his return.
They include an annual salary of £12 million, control over transfers and a get-out clause should Chelsea fail to qualify for the Champions League this season.
Despite him having strong backing from influential figures at Chelsea and around owner Roman Abramovich, these demands have been flatly rejected for now.
Is Mou out of order with these demands? What about the get-out clause? Give us your shout below...