Napoli have reiterated their intention to keep hold of Ezequiel Lavezzi and Marek Hamsik in the summer.
Lavezzi has been linked with a move to Chelsea and Manchester City this season, while Hamsik has reportedly been attracting the attention of West Ham United.
Speculation has claimed that Napoli could lose both Argentinian striker Lavezzi and Slovakian midfielder Hamsik at the end of the campaign.
However, the club's president Aurelio De Laurentiis says only a 'foolish' offer would persuade him to cash in on the influential duo.
"They are not on the market," De Laurentiis told Radio Kiss Kiss.
"I reaffirm it, unless there will be a foolish offer which would be impossible to refuse because, in that way, it would be possible to buy many other players.
"We are building a team that will always have more credibility."