And now reports have emerged that the relationship between England's best batsman and their coach, Andy Flower, has disintegrated to the point where the two will be unable to co-exist in the dressing room, leaving the future of both up swirling in the Sydney air.
Out of the adversity of a harrowing 5-0 Ashes whitewash, Flower and captain Alastair Cook have both said they are intent on forging a successful future for their team. But to do so they will need to form a united front on issues of personnel and tactics.
It was Cook who was reportedly the driving force behind Pietersen's successful reintegration, in autumn 2012, an achievement vindicated when the batsman played one of his finest innings to help his captain turn round England's fortunes on the way to a wonderful 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 a dreaded 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. "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. "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 biffing strokeplayers and nifty 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 10 months, before Pietersen's quest for a fifth Ashes series victory might begin.
"My fear is that England will make him a scapegoat," said Michael Vaughan, the former England captain. "And they 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 £30million and get Virat Kohli in'."
Where cricket does spend big money, though, is in the great golden cash cow that is the Indian Premier League.
It has been a constant source of frustration for Pietersen, who would command a huge fee at auction, but has been unavailable due to Test commitments in blustery English May - often against teams whose best players are absent, off bashing the ball in India instead. The issue may come to a head again in April.
England's other senior batsmen, Ian Bell - the only other survivor of the 2005 Ashes triumph - was also on Twitter on Tuesday, 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 told his followers. "Really appreciate the support through these hard times as well the good!"
Meanwhile, Ryan Harris, the Australian fast bowler who was man of the match at Sydney, revealed that although he needs surgery on his troublesome knee he will delay the operation to be a part of the team's tour to South Africa next month.
The injury-prone 34-year-old, who has rarely lasted a full series for Australia, considered having surgery during the 5-0 Ashes whitewash of England but it would have ruled him out of last two tests.
Instead, he played through the pain and took eight wickets as his side sealed their 5-0 series victory.