Chelsea had a £20million bid for the 21-year-old England centre-half rejected by Everton on Friday, but it is understood that a bigger offer is on the cards.
Speaking after the 3-1 loss to Arsenal in the final of the Asia Trophy on Saturday, Martinez indicated that any further interest in the player would not be welcomed.
“We pride ourselves on playing a certain way and educating our young players in a manner that they are going to always get attention from elsewhere and that is always a compliment,” he said.
“The other side is the disappointment of seeing a football club leaking such statements to the press and making it so open.
“That is not the way we would do it at Everton, we would not speak of a player who is registered at another club and there is no issue from our point of view – John Stones is an Everton player.
“We are not a selling club. We are not a club that needs to be worried about what other clubs put through the press.”
Chelsea boss Jose Mourinho has confirmed his side’s interest in the player, but refused to say if they’d come back in with a higher bid.
Speaking to Sky Sports News HQ on Chelsea’s pre-season tour in Montreal, Mourinho said: “We made a bid, the bid is there and Everton have the power to accept it or refuse it.
“This is between John Stones and Everton and I don’t speak about him because he is an Everton player.
“If we made a bid it is because we like the player, we don’t make bids for players we don’t like, but we respect Everton and respect every club that has a player and it is up to them – everything is in their hands.”
Asked about Martinez’s comments, Mourinho said: “The transfer window is open, when it is open every club and every player is open to bids.
“Bids come for our players, we make bids for other players and the process can be so simple, so I would advise Roberto to do the same thing as I do.
“If I get an offer for one of my players and I don’t want to accept any offer I say I don’t accept any offer, so you can make it very, very easy.
“If today I receive a bid for (Cesc) Fabregas in two minutes I will say I don’t accept any bid, game over, that’s it.”
Speaking at a sponsor’s event on Friday, Stones said: “I am very happy at Everton.”