Roy, a key part of the side that won the global crown on home turf four years ago, was named in the provisional squad last month and his long established opening partnership with Jonny Bairstow appeared to be inked in for next month’s tournament in India.
But the landscape has shifted quickly, with Roy suffering back spasms that ruled him out of all four ODIs against New Zealand – a series effectively planned as a fine-tuning exercise before the competition.
In his absence Dawid Malan has made a compelling case to take his spot in the first-choice XI, reeling off 277 runs at an average of 92.33 with a strike-rate of 105.72 and signing off with a superb Lord’s century.
With the versatile Harry Brook hovering in the background after surprisingly being cut from the initial list, Roy’s fitness issues could hardly have come at a worse time.
England are expected to formalise their picks next week, ahead of the September 28 deadline, but Buttler has reiterated head coach Matthew Mott’s suggestion that will be no formality.
Brook already has a place in a much-changed squad to face Ireland and Roy may be asked to join it to prove his form and fitness. For both men, the stakes are high in the coming days.
Asked if the final 15 was now set in stone after a 3-1 win over the Black Caps, Buttler offered a single, telling word in reply.
“Nope,” he said. Expanding on the subject, and Roy’s status, he added: “Obviously it changes and now you can let the dust settle on the series.
“We just have to find out (how he is). The biggest frustration for him is he wants to be fit and playing, affecting games of cricket for England. He’s been working really hard to be fit and available but we now have a few days where we can regroup – the coach, the captain, the selectors – and just work out exactly what we need to do moving forward.
“You don’t want to risk anything but at the same time you do want guys to play cricket. That’s our job, to play cricket and we all want to play.”
Roy’s status is complicated by his long tenure in the side. He was a key pillar of England’s white-ball revolution from 2015 and has played more ODIs in the last four years than anyone else, with 32.
Yet his output has diminished over the same period – with an average of 42.79 up to the 2019 final dropping to 31.78 in the aftermath.
England are not averse to ruthlessness, axing Roy on the eve of last year’s T20 tournament and going on to claim the trophy, but are wrestling with their commitment to their core players.
“We’ve tried to be a really loyal team and selection panel throughout. It’s something Eoin Morgan and Trevor Bayliss (former captain and coach) started, right at the start,” explained Buttler.
“If you ask people to play in an aggressive way then leave them out as soon as it goes wrong, it sends the wrong message. We’re asking people to take risks, so there will be failures along the way.
“We’ve reaped the rewards of been consistent with selection, so certainly you take whole picture in. You can’t just pick a World Cup squad from these four games because there’s a lot of thought and process that goes into looking into people as a whole.
“That’s been one of the hallmarks of selection but I think we can find out all the information over the next few days if we need to and make what will always be a really tough decision.
“We’re blessed with so many good cricketers in the white-ball game at the moment but in a World Cup, you can only take 15.”
Jofra Archer, another member of the 2019 group, is still under consideration as a travelling reserve as he comes back from another injury-ruined season but Buttler urged caution where the 28-year-old was concerned.
“He’s been out of the game for a while. He’s had his elbow and his back [injuries] and he’s still a young man who’s got a lot of cricket ahead of him,” he said.
“So there’s a massive duty of care to make sure that he’s fully fit for the rest of his career. It’s obviously exciting to see him in an England tracksuit and bowling, he’s a superstar. But we’ll find out more over time.”