The Argentine has been linked with top clubs across Europe in recent weeks.
Pastore told Gr Parlamento on Monday: “There has been no official offer from anyone, just a semi-official one from a Spanish club for about €25m. There has been nothing from Italy though.
“But, as I have said before, Pastore is priceless because he is not for sale.
“However, I do realise that keeping him here with us will not be easy and I think he’s worth around €60m.
“He is one of the best players in the world and is somebody who one day will win the Golden Ball.”