Zielinski has been heavily linked with both Liverpool and Chelsea in the past, but Napoli are keen to keep hold of their man.
The midfielder is currently midway through a five-year deal that expires in 2021, but Napoli are trying to extend his contract, pushing his release fee up to €150m.
Zielinski has been a regular under Carlo Ancelotti so far this campaign. He has started all but one game since the Italian arrived as the Partenopei’s manager.
The Pole has played eight games in all competitions, scoring two goals; both of which came in the 3-2 win over AC Milan last month.