Liverpool and Napoli are battling for Porto midfielder Hector Herrera.

Napoli have been in talks for the Mexico international for several weeks, but Liverpool are now threatening to trump the Azzurri with a superior offer.

Napoli have already tabled a bid of €15 million, but Porto are demanding a further €5 million for the deal to go through - and this has opened the door for Liverpool.

Mexican sources say Liverpool are not only in contact with Porto, but have assured the Lisbon giants they're prepared to match their asking price. Herrera's contract offer will also be far superior - and needs to be with Napoli in the Champions League next season.

A key in the deal is that former club Pachuca still holds 30 per cent of Herrera's registration - which is why Porto are pushing for as high a price as possible.