Napoli sports director Riccardo Bigon says they're yet to hear from Chelsea over Marek Hamsik.

The Slovakia international has emerged as an £18 million January target for Chelsea boss Carlo Ancelotti.

Napoli are aware of Chelsea's interest, though Bigon says: "There's been no request for Hamsik.

"There has been no official request or approach, Marek remains crucial for us and his future is not in question."