The Kevin Pietersen factor is top of the list of any number of variables which may yet complicate England's 'new era'.
Out of the adversity of a harrowing 5-0 Ashes whitewash, team director Andy Flower and Test captain Alastair Cook have both said they are intent on forging a successful future for their team. To do so they will need to form a united front on issues of personnel.
They will not always instinctively agree, of course, and when it comes to Pietersen there is no compelling evidence yet that they do concur on whether he can still be a cornerstone of England's regeneration in time for the 2015 Ashes.
It was Cook who was reportedly the driving force behind Pietersen's successful reintegration, in autumn 2012, an achievement vindicated when the mercurial batsman played one of his finest innings to help the captain turn round England's fortunes on the way to a wonderful Test series victory in India last winter.
Scroll on a year, though, and there has been no such impact by Pietersen – or anyone else in an England shirt, for that matter – in a hapless descent to the dreaded Test series whitewash in Australia.
In its aftermath, Flower unequivocally committed himself to stay on as Test coach – adding he has great faith in Cook to put his stamp on a team for the future. Pietersen's intentions appeared far from guaranteed, until he made them so via Twitter.
Flower, and Cook, may be interested to discover – if, like millions of others, they did not know already – that Pietersen wants in. "I want to thank all the England fans for their terrific support – and I'm determined to help regain the Ashes in 2015," he wrote.
"I'm very disappointed to lose 5-0, and not to score more runs personally. Tough tour against a top-class team."
After Cook's duties as England's one-day international captain are completed over the next three weeks – no easy task against a rampant Australia, with a stack of damaging stroke-players and wicket-takers at their disposal – he and Flower will have four months to work out, along with the selectors, a strategy for seven Tests next summer.
Beyond that lie just another five Tests, spread over ten months, before Pietersen's quest for a fifth Ashes series victory begins – perhaps.
Advice for England's 'brains trust' is plentiful, and one former captain – an Ashes-winning one at that – is concerned about a hasty and costly rejection of Pietersen's talents. Michael Vaughan said: "My fear is that England will make him a scapegoat, and England will feel that the only way they can move forward is without Kevin Pietersen.
"Cricket's got to be careful – because, while in football you can sign a new striker, in cricket you can't say 'you know that number four slot, let's go and pay £30 million and get Virat Kohli in'."
Pietersen, 33, helped to establish Vaughan's legacy – and launched his career for his adopted country with a bang in that Ashes victory of 2005. He is one of just two survivors from that team, and the other is not nearly so divisive.
Ian Bell, still only 31 and feasibly with another five years or more left him as a world-class batsman, was also on Twitter yesterday – voicing his own regret at England's under-performance over the past two months. "Devastating to lose 5-0. Thanks also to all the travelling supporters," he wrote.