Napoli have struck personal terms with Porto striker Jackson Martinez.
However, they still must convince Porto to sell the Colombian.
"There is an agreement with the player," Manuel Manzo told Sky Sport Italia. "However, one with Porto is missing and they don't want to sell.
"The only chance of a move happening, in my opinion, is if the Azzurri pay the 40m rescission fee clause which is in his contract. Otherwise he won't move."