Bayern Munich general manager Uli Hoeness cannot rule out selling Franck Ribery.
Chelsea and Manchester United are chasing the Frenchman, who is also wanted by Real Madrid.
Speaking on the day Louis van Gaal was officially unveiled as the Bavarians' new coach, Hoeness revealed what he had told Real Madrid president Florentino Perez in their last telephone conversation.
He said: "I asked his right-hand man Pedro Lopez Jimenez, since Florentino does not speak English all that well, whether he knows the game Monopoly.
"I told him that Bayern had bought Mayfair on Monopoly two years ago and you don't give Mayfair away that easily.
"We would only consider it if somebody did something crazy."
Hoeness added that there is "no new offer and there never was an offer", but that he had spoken several times with Lopez.
"There were a few enquiries from the top people at Madrid because we are only prepared to speak with the president or his right-hand man," he added.
Van Gaal also missed the opportunity to end the speculation over the France midfielder, saying only that he "always wants to keep hold of the best players as a coach" before adding that it depends on a number of factors including the "atmosphere" and whether the player fits into the "holistic philosophy" he intends to implement.