Head coach Brendon McCullum believes England’s revamped Test side has developed a “harder feel” after starting the summer with a ruthless 3-0 clean sweep over the West Indies.

A handful of significant changes were made at the start of the series, with record wicket-taker James Anderson nudged into retirement and 100-cap veteran Jonny Bairstow ousted alongside fellow wicketkeeper Ben Foakes and spinner Jack Leach.

England’s appetite for change grew after a 4-1 defeat in India at the turn of the year, with McCullum and captain Ben Stokes opting for an injection of fresh blood in the shape of Gus Atkinson, Jamie Smith and Shoaib Bashir.

The average age of the axed quartet is 34.75, compared to 23.33 for the trio of young recruits. All three stood up to be counted as the hosts reeled off three thumping wins – by an innings and 114 runs at Lord’s, 241 runs at Trent Bridge and 10 wickets at Edgbaston – and McCullum thinks the changes have helped develop a new steeliness that can carry the side to the next level.

“No changes are ever easy, are they? But we knew we needed to make a couple of improvements as a side and we brought in some new faces,” he said.

“The guys who have been in there before did a really good job for us, and it’s certainly no slight on them, but we felt that we needed to introduce some new guys.

“You don’t ask for instant gratification when it comes to them but the way the series played out you’d say the guys have certainly shown they’re good enough at this level.

“What we’ve seen from Gus Atkinson, from Shoaib Bashir and Jamie Smith, is that international cricket is where they belong and they’ve performed accordingly.

“Sometimes when you lose you have a period of reflection and what we’ve seen is a team which has bounced back with a bit of a harder feel to it. I think we’re a stronger team now than we may have been in the past.”

The most dramatic change has, of course, been Anderson’s removal from the frontline after 21 years of service and 704 Test wickets.

Rather than joining his old partner Stuart Broad in the commentary box, the 41-year-old transitioned immediately into the role of fast bowling mentor. Back in the dressing room just 48 hours after his emotional farewell at Lord’s, Anderson has impressed McCullum with his input.

“What Jimmy’s given in the past couple of matches is quite incredible. He’s fitted seamlessly into our group of coaches,” said McCullum.

“It’s never easy but he seems really content right now, it’s great to have him and I feel very lucky that he’s part of our group.”

The focus now is how Anderson can help coax the best out the attack as they build towards succeeding on the faster, truer tracks of Australia when the next Ashes series comes around.

“With the bowlers now we’ve got some pretty good ammo that we are going to need on flat wickets when times arise,” McCullum said.

“Gus has touched 90mph, been able to jag the ball off a good length and also been able to operate a bumper plan for a period of time. The way Chris Woakes bowled was outstanding. Then you add the speed of Mark Wood, which is quite frightening really. Shoaib Bashir and Stokesy are in there too – and these other guys waiting in the wings. We’re not the finished article but this series is a step forward.”

Elsewhere, speculation continues to mount around the future of England white-ball coach Matthew Mott, who is expected to lose his job at the conclusion of a review by director of cricket Rob Key.

McCullum declined to wade into the debate but offered a more general word of support for his limited-overs counterpart.

“I don’t know how it’s going to work out, to be honest, I haven’t really followed it because you’re worried about doing your own job,” he said.

“Motty is a good bloke and a very good coach. Whatever happens he’ll be fine.”