Ashley Williams is expected to complete a £10m move from Swansea City to Everton on Wednesday – part of a central defender transfer chain Mick McCarthy has called “bonkers”.

While Gylfi Sigurdsson agreed a new four-year deal on Tuesday, the Swans skipper is understood to be close to signing for the Merseysiders, rather than returning to the Liberty Stadium from his extended break following his efforts with Wales at Euro 2016.

Williams was due to link up with the rest of the Swans squad on Wednesday, but manager Francesco Guidolin has been told to prepare for the Premier League opener against Burnley without his inspirational captain.

Everton’s determination to push through a deal has been motivated by the need to replace England defender John Stones, who is expected to join Manchester City in a £50m deal.

That move – and the chain it has set in motion, with the Swans having already signed Dutchman Mike van der Hoorn from Ajax – has been criticised by McCarthy, the Ipswich Town and former Republic of Ireland centre-half.

“These figures – £50m for John Stones – and the effect they are having on the rest of us – are just bonkers,” said McCarthy.

“It’s being driven by the new TV money and doesn’t reflect the quality or the improvements of the players at all.

“You can’t tell me that a player who was valued at £30m or £40m last season is now worth £10m more.”

Swansea, however, appear to have concluded that £10m for Williams – who will turn 32 this month – is a sage piece of business.

The national captain has just come off the longest and most emotionally draining season of his career and although he has been among the club’s most consistent performers over the past eight years since he joined from Stockport for just £400,000, it could be that both club and player sense the time is ripe for change.

Williams, though, will take some replacing. Not only has he played 349 matches for the club in those eight seasons, but he has long been the heartbeat of the team on the field and a rallying point off it during times of turbulence.

Guidolin has been a big admirer of Williams during his short spell in charge, but the move for 23-year-old van der Hoorn, who played 16 matches for Ajax last season, may have signaled an awareness that Williams would be moving on.

The Italian can also still call on Argentine international Federico Fernandez as well as Jordi Amat, the Spaniard who arrived at Swansea three years ago, but is still only 24.