Everton remain determined to hang on to John Stones amid reports of a fresh €43million bid being made for the defender by Chelsea, according to reports.

The Toffees have already rejected two offers from Chelsea over the summer for the 21-year-old England international.

And while Everton would neither confirm nor deny talk on Tuesday that they had turned down a third bid of £30million, it is understood the Merseyside outfit’s stance on the matter has not changed.

That is that Stones is not for sale — something stressed by Everton boss Roberto Martinez last week.

Speaking on Thursday, Martinez said: ”I have said before the player is not for sale and that is the end of it.

”Our situation has been very clear from the beginning. We are not a selling club who will lose our best performers.

”He is very important player for us and we are looking forward to seeing the best of John over the next few seasons, not just the next few weeks.”

Speculation of Chelsea returning for Stones has heightened after John Terry was substituted by Jose Mourinho for the first time in 177 Premier League games in Sunday's 3-0 loss at Manchester City.

After the match, Mourinho said: “The point was not to take John out, but to put (Kurt) Zouma in. I want to have my fastest player on the pitch and not on the bench.”

Mourinho has spoken of his lack of first-team defensive options, with five defenders before Baba Rahman’s arrival made it six.

The 21-year-old Ghana left-back signed from Bundesliga side Augsburg on Sunday evening.

Speaking prior to the start of the campaign, which has begun with a Community Shield loss to Arsenal, a draw with Swansea and a loss to City, Mourinho said: “We have five defenders and we cannot go to the Premier League with five defenders. That’s our weakness. Five is not enough. That’s obvious.”

Mourinho was also asked how many defenders he needed ahead of the season curtain-raiser.

“Seven plus a quality kid,” he said, saying Ola Aina would be promoted to the first-team squad when needed.

It means Chelsea still have one defensive position to fill, but Mourinho has also spoken of a determination for his side to continue to show their new-found financial restraint.

It is something Everton may test.

Meanwhile Florian Thauvin is expected to undergo a medical on Tyneside on Wednesday as he closes in on a big-money move to Newcastle.

It’s believed the 22-year-old Marseille winger is due to head for the north east with the two clubs in advanced negotiations over a transfer the Magpies have targeted for some time.

Thauvin was identified as a potential signing by chief scout Graham Carr more than two years ago and the club has been monitoring his situation since.

However, managing director Lee Charnley has now made his move and head coach Steve McClaren will hope the deal can be pushed through after a mixed start to the new Barclays Premier League season.

McClaren was assured of significant investment in the squad when he accepted the job in June with owner Mike Ashley having signalled his intention to commit funds to the task of ensuring there is no repeat of last season’s desperate fight for top-flight survival.

The arrivals of Georginio Wijnaldum, Aleksandar Mitrovic and Chancel Mbemba have gone some of the way to fulfilling that mission, but McClaren indicated last week that he was hopeful of further additions, and Saturday’s 2-0 defeat at Swansea illustrated the club’s enduring need for reinforcements.

Newcastle have turned to left winger Thauvin in a bid to to inject pace and invention into the team and create a fresh supply line for strikers Papiss Cisse and Mitrovic, as well as attacking midfielders Wijnaldum, Moussa Sissoko and, when he is fit, Siem de Jong.

Compatriot Remy Cabella, who has struggled to adapt to the physicality of English football, could head in the opposite direction with reports in France suggesting Marseille want to take him on an initial loan with a view to a permanent switch as part of the deal.

However, the negotiations are understood to be delicate and as yet, incomplete.

The Magpies look set to go to the wire once again as they attempt to complete their business before the transfer deadline with a striker — they have spent much of the summer trailing QPR striker Charlie Austin — and defenders still on McClaren's wish-list.

They have taken just a single point from the opening two league fixtures — they drew 2-2 with Southampton at St James’ Park during the opening weekend of the campaign — and travel to Manchester United on Saturday before welcoming Arsenal to Tyneside.