Everton have been credited with interest in Sissoko for over a month and Tottenham had a £16m offer for Sissoko turned down earlier today with Newcastle reported to be holding out for £30m for the France international.
Sissoko, who has wanted a move away from Newcastle all summer, impressed at Euro 2016 and if Koeman ends up signing him, he will hope the Frenchman continues his fine form.
Newcastle Manager Rafa Benitez: “Moussa is now the big name in the market – if someone wants Moussa, they have to pay.
“If we are happy with the price, and he is happy, then we can maybe consider.
“But if we are not happy, then he can stay here and I will be really, really pleased to keep him.”