In between autographs and selfies were occasional grimaces skywards, wondering how much the dark clouds had left. Plenty, as it happens. Steadily, the crowd diluted and, eventually, Buttler retreated inside for cover.

Despite not playing at all during this white-ball finale to the 2024 English season due to a calf injury, he remains the big-ticket draw. And thus, a conundrum still to solve. Though he adopted a similar role to Ben Stokes during the Test series against Sri Lanka - rehabbing a torn left hamstring but on deck for every day of it - this rewarding of hardy punters braving the damp was the most statesman-like duty England's permanent limited-overs captain has performed.

Buttler was far more withdrawn than the Test skipper throughout his hands-off brief. Sky's cameras had to zoom in to find him on the back row of the home viewing balcony at Bristol, wrapped up warm and making merry with players and coaches, as pundits used the rain delay to pontificate over his part in this white-ball regeneration.

Sunday's finale capped off a September that began with one clear objective from on high. Fresh from being announced as a replacement for Matthew Mott after two unsuccessful World Cup defences in nine months, Brendon McCullum identified the key to revitalising the set-up was to cheer up a "miserable" Buttler.

Beyond the long-lens smiles, a man who was lucky to keep his job when Mott was relieved of his has by all accounts been buoyed by what has been a promising first stage of this latest "reset". A drawn T20I series and a 3-2 loss to the defending 50-over champions having been 2-0 down showed there is plenty for him to work with going forward.

Tresothick has essentially been acting as McCullum's surrogate before the Kiwi assumes the job at the start of 2025. McCullum has been involved from afar while preparing for the upcoming Test tour of Pakistan. Communication has been regular, ranging from input in selection matters, such as personnel and roles, along with a handful of debriefs after games.

"We are always planning ahead to when Brendon is coming in and the bigger tournaments," Trescothick said. "That's going to be the real judge, isn't it? Bilateral series are great, but the real pinnacle is the Champions Trophies, the World T20s and the World Cups."

It will be the next bilateral, against West Indies at the end of October, when Buttler will return in a playing brief. And it was instructive that Trescothick felt the need to nip any talk of finding a spot in the XI for him in the bud, while admitting the exact guise of his return is up in the air.

"Let's make it clear, he will come straight back in. At what position, I don't know. We'll look at that for the Caribbean."

The proximity to the tour of Pakistan - the third Test is scheduled to finish three days before the first ODI in Antigua on October 31 - is likely to mean Buttler reassumes the wicketkeeping. Jamie Smith is likely to be prescribed a rest ahead of flying out to New Zealand for that three-Test series in November, while Phil Salt's average of 19.90 against Australia suggests he has still not got to grips with the longer of the shorter formats.

Set against Salt's moonlighting for the T20I series, and Ollie Pope deputising for Stokes for the last half of the Test summer, Brook stands out as a leader in waiting. Trescothick praised Brook's ability to marshal while setting the standard with the bat, finishing as the leading run-scorer across both teams in the ODI portion, with 312 at 78.00.

"He reads the game very well and the way he captains - the field settings and the decision-making - is very positive. He is quiet and unassuming but just gets the job done on everything he has to do."

Brook said he enjoyed his first taste of international captaincy having led England Under-19s before honing his leadership for Northern Superchargers this summer. He went on to state he looked forward to "taking a seat back and letting Jos do it again".

For how much longer remains to be seen. Brook's impression has been strong enough to bring that conversation forward, at least among those watching from the outside. But the person who will bring that conversation to the table will be Buttler.

This is still his patch, and the immediate priority is ensuring he slots back in more comfortably than ever before. Whatever shifts and conversations there have been against Australia, whether around playing roles, off-field bonhomie, or simply broader changes of perspective, they have been as much about emboldening the next generation as creating an environment for Buttler to flourish. As McCullum put it, the goal for however long the 34-year-old has left, "is just to enjoy it".

"I expect him to find it really enjoyable going forward," Trescothick said. "Having worked with Brendon and the other coaches and the style that Brendon wants to implement into the white-ball stuff, it's what's been going on before [with the Test team].

"There's no reason why Jos won't fit back into that mould, score millions of runs, captain well and fit back into the team perfectly."

There are reasons, however, all of which remain untouched because of his on-field absence over the last month. The next step, for England and Buttler, is working through them.