Napoli fear losing Dries Mertens to the Premier League this summer.

The Belgium international has seen new contract talks stall amid claims of him meeting with Manchester United representatives last week.

Il Mattino says Napoli have big concerns that Mertens' head has been turned.

A new contract offer is now being drawn up, which will run to 2021 and be worth €3 million.

But it will fall well short what United can put on the table.