Juventus legend Gianluca Vialli feels Napoli haven't enough to challenge for the title.

Napoli drew 0-0 with AC Milan on Sunday.

Vialli said: "Sometimes Napoli did not express itself at the levels of the first two thirds of the championship. I think a few have stopped believing it, they have lost their conviction and this then translates to less energy on the field, less creativity.

"I think Dries Mertens is not very energetic at this time, so I wonder if they should try (Arek) Milik."