The Belgium international is expected to have a new deal signed next week despite suggestions he could leave at the end of a superb season
Napoli president Aurelio De Laurentiis expects Dries Mertens' future to be resolved in a week and says coach Maurizio Sarri can stay at the club for life.
Mertens has been on fire for Napoli this season, scoring 30 goals in 43 games in all competitions for a side pushing for a second-place finish in Serie A.
The Belgium international is contracted until 2022 but the Stadio San Paolo outfit are looking to tie him to a longer deal, while Manchester United are reportedly interested.