The arrival of Victor Osimhen could prompt Gennaro Gattuso to change the Napoli system to a 4-2-3-1.
According to Corriere dello Sport, the 4-3-3 formation will not be suitable because Dries Mertens is now too old to play entirely on the wing of a trident attack and will struggle with the extra work-load.
Instead, the manager is believed to be planning a 4-2-3-1 system with Mertens, 33, Lorenzo Insigne and Eljif Elmas or Piotr Zielinski in support of the record summer signing Osimhen.
Napoli spent €80m including add-ons with some youth team players to sign centre-forward Osimhen from Lille.
Osimhen spent one season at Lille, scoring 18 goals and recording six assists in 38 appearances across all competitions for the French Ligue 1 side.