John Terry
John Terry believes England colleague John Stones could be a good asset for Chelsea in the future as he edges closer to retirementGetty

Roberto Martinez has lambasted John Terry for his comments on Chelsea's ongoing pursuit of Everton defender John Stones, claiming that they were 'llegal" with regards to established conduct when openly discussing players at other clubs.

The 21-year-old has established a reputation as one of the Premier League's finest young defenders since moving to Goodison Park from Barnsley in January 2013, attracting strong interest from Jose Mourinho as the Portuguese gaffer looks to further strengthen his centre-back options in the long term.

Reports from the London Evening Standard suggest that Chelsea have already seen two bids for Stones rejected so far this summer, the latter of which was supposedly worth £26m ($40.3m), with Everton believed to be seeking to receive approximately £34m for one of their most precious and marketable assets.

While doubt has emerged over whether the champions will return with a third offer before the current transfer window closes on 1 September, Terry recently appeared to endorse such a deal by telling Sky Sports: "One day, I won't be in the team but Chelsea are looking to the likes of John Stones for the future, so the club will continue to grow and do well."

Those comments have gone down very badly indeed with Martinez, who went as far as to label them as"wrong" as he bids to repel interest in Stones to help Everton return to contention for European qualification after last season's disappointing 11th-place finish.

"That is wrong; that is illegal. The rules don't allow you to comment on players who are registered at other clubs in that open manner. That is disappointing," he was quoted as saying by The Guardian during a press conference held prior to the Toffees' opening match of the 2015/16 campaign at home to newly promoted Watford.

"We have a fantastic relationship between the two clubs. In the past we made our biggest investment in Chelsea [when signing Romelu Lukaku]. We all know there are rules and regulations and it is something we don't want to see when other clubs speak about your players. It is wrong and it shouldn't happen. As clubs we have a good understanding of where we are."

Martinez, who was delighted with James McCarthy's decision to sign a new five-year contract on 6 August in order to ward off interest from the likes of Tottenham and Manchester City, further reiterated that Everton simply do not need to offload their best players in order to improve financially and that Stones is not for sale.

"What you can control is your own finances at the football club and we are not a football club that has to sell to balance the books. If you think we need to sell John Stones to balance the books: that is not the case. He is not for sale - we have said that many times. He is not for sale," he added, according to Goal.

"I am not stupid enough to say I know what will happen or that I have a crystal ball but I have always said John Stones is not for sale. We have had one or two bids for a player who, in my eyes, potentially can be the best centre-half England have produced, and we have not accepted it. There is no deal on the table so move on."

Stones picked up a knock during Duncan Ferguson's testimonial against Villarreal last time out, a game which saw Wayne Rooney pull on the blue of Everton for the first time since leaving for Manchester United 11 years ago, but he is expected to be fit to start for the visit of Quique Sanchez Flores and Watford.