Joe Root has been passed fit for the first one-day international against Australia after recovering from a viral illness.

Root was hospitalised on the final morning of the Ashes in Sydney having been stricken with a bad case of gastroenteritis and sat out Thursday’s warm-up match against a Cricket Australia XI.

But the Test captain has finally shaken the bug and will give the tourists a major boost by reclaiming his place in the top order for Sunday’s Gillette Series opener.

The 27-year-old took a full part in England’s net session, which took place indoors due to a downpour at the MCG, and emerged in rude health.

Limited-overs skipper Eoin Morgan said: “Joe is good and should be fit to play tomorrow. He’s extremely important. He’s been a fantastic leader within the group and, on top of that, there’s the weight of runs he’s scored and the manner that he’s scored them.

“He’s obviously a key part. He’s a very versatile player and can score in any strike-rate that needs to be required, given the situation. He’s very important.”

Morgan did not offer any further clues about the make-up of the England team but hinted that all three openers – Jonny Bairstow, Jason Roy and Alex Hales – could be accommodated.

That may lead to Hales slotting in at number three, with Sam Billings vulnerable to any such switch.

“That is an option,” said Morgan. “Our batting has been our strength over the last couple of years and we don’t want to compromise that, so it’ll be a case of picking our strongest six, plus an all-rounder possibly, or an extra seamer.”

While the recently concluded Ashes series unfolded at an attritional pace, both sides are likely to approach the next five games in a more cavalier fashion.

England rebranded their limited-overs game dramatically since they were last on these shores, the abject 2015 World Cup campaign which exposed some outdated ideas and became a watershed moment for the team.

Morgan is clear there is no going back, and said: “That tournament had quite a significant role for us, really. After that, a line was drawn in the sand and we were given clear directives that the goal was the 2019 World Cup. To bridge the gap between where we were at in that World Cup and, say, being in the semi-final or the final was the first port of the call and bridging that gap came quicker that we ever thought it would.

“We got a huge amount of confidence from the selectors and Andrew Strauss, our director of cricket, gave absolute clarity in what we wanted. We certainly thrived on that. It’s not often you get free rein and ambition to be adventurous as you like.”