Buttler stepped in successfully at the last minute to deputise for Eoin Morgan after a back spasm ruled England’s white-ball captain out of the second one-day international in Cardiff on Saturday.
An update on Morgan’s fitness, along with that of Ben Stokes and Chris Woakes, is expected later today.
The two key all-rounders were ruled out of the first part of the ongoing five-match series with leg injuries, and the indications so far are that Woakes’s thigh problem is likely to keep him out for significantly longer than Stokes’s torn hamstring.
Without all three players, however, England proved good enough under Buttler’s captaincy to take a 2-0 lead with a 38-run victory in the weekend run-fest at Sophia Gardens.
If it falls to the wicketkeeper-batsman to take the reins again, he will be ready as England target an unassailable 3-0 advantage in Tuesday’s day-night match in Nottingham.
After he had hit an unbeaten 91 in a total of 342-8 which also featured a century from opener Jason Roy, Buttler had two more critical roles to play as he directed England in the field from behind the stumps.
“I enjoyed it,” he said. “It’s a bit more stressful going through lots of decisions, (and) the buck stops with you. As vice-captain you can suggest a few (ideas), and hide behind that.”
Buttler’s previous experience of leading England came in a hard-fought series victory in Bangladesh in October 2016 – Morgan was absent because of his security concerns over that tour.
There is no shortage of ODI experience in the ranks of the world No 1 team, and Buttler added: “The guys know what they’re doing. It’s a very good side to captain.
“At times it captains itself, with defined roles for the players and a lot of experience in the group.”
As in Bangladesh, Buttler was happy to keep the gloves, despite his extra responsibilities and even though England had two other wicketkeeping options.
“I don’t think it’s impossible to do so,” said the 27-year-old.
“Lots of captains have been wicketkeepers as well.
“You’ve got a pretty good position to see what’s happening and what’s going on, so I don’t think it’s a problem.”
England’s mettle was tested as an inspired Shaun Marsh kept Australia just about in the contest in Cardiff, until Yorkshire duo Adil Rashid and Liam Plunkett took the crucial wickets to close out the match.
It all left Buttler acknowledging the “potential” of pulling off a 5-0 whitewash, but warning England still have plenty of work to do in both the immediate and longer term.
“There’s a World Cup round the corner, so we need to keep polishing up in those areas we can improve,” he said.
“It’s very important for us to continue to show why we got ourselves to number one in the world. We have to keep improving, keep working very hard.
“A by-product of that is winning the series in comprehensive fashion.
“But we’ve got to keep going game by game, and not get ahead of ourselves or complacent.”
Centurion Roy was quick to give a glowing mention to Yorkshire’s Jonny Bairstow, his opening partner in Cardiff, for setting the tone with a rush of early boundaries after England were put in on a cloudy morning.
Roy admitted he had his own national-record 180 in his sights until he was caught-behind in the 36th over.
Nonetheless, as he picked over his innings with England batting coach Graham Thorpe, he concluded it was the best of his five ODI hundreds to date.
“I had a long discussion with Thorpey just after I got out and said it was probably my favourite innings - as far as the tempo of it, the way I knuckled down early,” said Roy.
“I went through some difficult patches, but then came out the other side. When I wanted to start expanding my game, unfortunately I got out - but I was still happy.”
Roy’s brilliant batting can sometimes have a seat-of-the-pants look to it, but this time he appeared more measured than ever – all the more impressive after his second-ball duck in the first ODI at The Oval.
“I was able to knuckle down and get myself in,” he added. “(Jonny) is great to watch isn’t he at the moment? He’s in some incredible form.
“It was a nice feeling to be able to just relax and take a watch.”
It was heartening too that Roy hit such heights in his first ODI back at this venue, where he was left out of England’s Champions Trophy semi-final team last summer.
He said: “It’s disappointing to be dropped at any ground. Playing for England is a huge honour.
“It was a big aim of mine to come back after a long winter and start well. I’ve put in a lot of hard work over the last two days, and got a few rewards here.”