"He has a bit of class about him," McCullum said, having been impressed by Bethell's calmness and maturity. "I'm pretty disorganised with stuff; I'm always looking for my car keys or phone charger, but Bethell always has his.

"He is one of those guys who is very meticulous with his preparation and planning which then lets his flair and creativity show on the big stage. He is a guy we can't be more happy with after what he has achieved in this series and I think he has shown that international cricket is for him."

A broken thumb sustained prior to the second day's play of a warm-up match against a Prime Minister's XI in Queenstown ruled Cox out of the tour. Shorn of another full-time gloveman, England turned to their vice-captain Pope, who obliged, dropping down three spots to six to concentrate fully on the role. Thus Bethell, the spare batter, was given an opportunity to flex at the business end of the batting order.

Both Bethell and Pope left New Zealand on Wednesday morning to join their Big Bash League teams, Melbourne Renegades and Adelaide Strikers, respectively. But it was 24 hours earlier that their situations came to a head at Seddon Park through the prism of their ugly dismissals.

Pope's dismal attempt to ramp Matt Henry, costing him his off stump for 17, drew the most ire. Legendary Kiwi commentator Ian Smith, who was on air with Sport Nation NZ at the time, was particularly scathing: "Sit him down in a cold dark room and put some electrodes on his head and say 'what were you thinking Ollie?'"

Bethell, meanwhile, had shown impressive gumption to survive a blistering spell from 6ft4in quick Will O'Rourke, before scything the retiring Tim Southee to deep point. It was the second chance at a first professional century Bethell has spurned on this trip after falling four short in Wellington last week.

The messaging throughout the tour has been that Pope will resume the position he has owned since the start of Ben Stokes' tenure in 2022. Though he averages a tidy 40.28 in that slot, Bethell's tighter technique and assurance at the crease is regarded by some as a better fit for three compared to Pope's general freneticism.

All this presents a conundrum when Smith returns to the fold. England's next Test engagement comes in May, a one-off four-day match against Zimbabwe at Trent Bridge. And while no decision needs to be taken just yet, McCullum admitted Pope's spot is no longer guaranteed because of Bethell's strong first impressions.

"Look, it is a good problem to have," McCullum said. "We were all a little unsure whether Beth could play at three when we asked him to do it but we saw the talent in him and he has performed very well against a very good bowling line-up.

"They are good problems. We will work it out. Popey has done really well for us and to have now Beth there as well, you are adding some depth to your batting stocks. They are good decisions to have and we will not make them in the next few days. When we get together again in a few months' time we will work all that stuff out."

Results have been mixed, with nine wins and eight losses across the 17 Tests, amounting to three series victories and two defeats. Nevertheless, McCullum feels the squad is now better equipped to take on the challenges that lie ahead next year.

"The emergence of [Brydon] Carse, Bethell, [Gus] Atkinson and Jamie Smith. We have got other guys who have taken on different roles as well. The skipper got injured in this Test which we don't think will be too bad but even his continued development as a captain and leader in the group is being backed up as an allrounder as well.

"Overall, I think we're a better team than we were back then (January), albeit we had some guys who did well for us. Now I think we have a team which is capable of being able to take on the best teams in the world, and soon we will find out."

The new year also brings new scope for McCullum as the white-ball teams come under his control. After a short break, his first duty will be a limited-overs series in India ahead of the ICC Champions Trophy in February. Naturally, he is enthusiastic about the prospect of bringing his Test ethos to England's ODI and T20I squads, after a year of failure at both World Cups.

"I'm excited by it, we'll find out, right?" he said. "There's not too many times in life you take things on with meat on the bone and that's why I took on the Test job initially.

"I'm excited about it, with Jos [Buttler] there as captain. There's something there to work with. Get it right and we could achieve some pretty cool stuff over the next couple of years."