Liverpool and Tottenham Hotspur will have to cough up £35 million if they are they are to prise Jackson Martinez away from Porto, the club have confirmed.
The Colombian striker was in sensational form for Porto last season after netting 29 goals in 38 appearances, guiding Porto to the league title.
Both Liverpool and Spurs have been linked with the striker in recent weeks with Napoli also throwing the hat in to the ring.
The Portuguese champions confirmed that Napoli have agreed a £33,000-a-week deal with the South American but are no closer to reaching an agreement over a fee.
Porto are insisting that their latest Colombian sensation will not leave the club for below his release clause.
"There is an agreement with the player," Manuel Manzo told Sky Sport Italia over Napoli's interest in Martinez.
"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 (£35m) rescission fee clause which is in his contract. Otherwise he won’t move."
Reports in Italy suggest that Napoli are refusing to budge from their original £28m offer after they signed Gonzalo Higuain from Real Madrid.
Tottenham have seemingly turned their attentions to Roberto Soldado of Valencia but could be tempted in to a move for Martinez if Gareth Bale is sold to Real Madrid for a huge fee.
The same token goes for Liverpool who may need to find a replacement for the want-away striker Luis Suarez.