Pietersen's prolific run-scoring has not stopped this year, but England's best batsman has endured some difficult times in 2009
Six months after he quit as captain, England's Ashes hopes once again rest heavily on the broad shoulders of Kevin Pietersen.
Even by his standards, the South Africa-born batsman has enjoyed a lively few months.
Firstly, there was the debacle over the way he was forced to step down as skipper only five months in to the job in January, after it emerged there was a rift between him and then coach Peter Moores.
WHAT THEY SAY ABOUT KP
He's their class player and he rises to big challenges, so we must keep him under control
Australia captain Ricky Ponting
He then admitted to being "at the end of my tether" in March over a lack of success on the West Indies tour, before suffering an Achilles problem at the start of the summer which, for a short time at least, seemed to threaten his participation in the Ashes.
Nothing is ever simple when it comes to KP, but what England fans are desperate to know is whether these problems will impact on the Pietersen that takes on Australia.
After all, with a Test average of just over 50, Pietersen is comfortably the most important batsman in England's line-up and with his explosive style, he remains a potential match-winner every time he steps out into the middle.
So far, so good - Pietersen's average since he resigned the captaincy is almost exactly the same as it was before, and the Achilles injury that troubled him at the start of the summer appears to be easing just in time.
Ray Jennings coaches Indian Premier League side Royal Bangalore Challengers, who Pietersen captained for two weeks in April, and he believes England have little to worry about.
"There is no doubt that Kevin is one of the best in the world at focusing 100% on his cricket, no matter what else is going on," Jennings told BBC Sport.
"He is such a strong guy because someone who stands his ground so much exposes themselves in everything they do, so you need to be mentally tough to overcome things that are thrown your way.
"He's a hell of a strong character, he never stops backing himself and that's vital.
"It'll be difficult for one person to make all the difference in the Ashes, but if Kevin Pietersen fires, the impact will be bigger than it would be for many other players."
That is because Pietersen has a remarkable ability to take the game away from opponents in a flash - and Australia captain Ricky Ponting has already targeted him, citing his wicket as the key one for the tourists.
Pietersen remains undaunted: "I'm challenged a lot by bowlers and opposition. Most teams pretty much target me now - and it makes me simplify things and make sure I'm going through my little routines."
Yet despite the air of serenity, the cloud of the captaincy debacle still hangs over Pietersen, especially as he has admitted to feeling badly let down by the ECB over the affair.
Pietersen quit as skipper on 7 January after it emerged he had a difference of opinion with Moores, who was sacked on the same day.
England colleague Andrew Flintoff believes Pietersen was left distraught by the events which led to him resigning just five months in to the job.
"He was passionate about it and I think losing it so soon will eat away at him," said Flintoff. "It's unfinished business... throughout his career he's never struggled."
Moores (left) and Pietersen did not see eye to eye, with both losing their jobs
Jennings says he would not be surprised at all to see Pietersen get another chance as England captain.
"I have to say, during my time with Kevin at the IPL, I actually found him to be one of the better captains I have worked with," added the 54-year-old former South Africa coach.
"He was respectful, loyal and enthusiastic, both to me and the players. He's a gentle guy, a caring guy too - I saw him do so many things that made me very proud to have a guy like that leading my side.
"There's no doubt I can see him as England captain again one day, he has got the mind and leadership qualities to do it, or to be captain of any team.
"One failure doesn't mean to say that Kevin is no good for the job, because that failure can be down to all sorts of things. Walt Disney failed in business 20 times and was successful the 21st time."
Pietersen will not be thinking about the captaincy right now, though. In Andrew Strauss and coach Andy Flower, England have produced a combination that appears to work - and Pietersen, pleased that the team is heading in the right direction, has confessed his admiration for the pair.
"Everyone knows how happy the England team is, how excited the boys are, how everyone's gelled and how well Straussy's doing," he said.
"The progress made over the last six months - fair play to both Andys - has been absolutely fantastic. We've all bought into it and we're a happy dressing-room."
England and Pietersen's immediate focus is on regaining the little urn that Australia won back with a crushing 5-0 whitewash in 2006-07.
WHAT THEY SAY ABOUT KP
Is he vulnerable? There's pressure on him, so we'll look to get him as cheaply as we can
Australia's Mitchell Johnson
Pietersen more than played his part in the 2-1 series victory four years ago, producing a stunning knock of 158 in the final Test at The Oval to help England regain the Ashes for the first time in 18 years.
The 29-year-old says he is expecting a stern examination again this time around, despite the retirements in the last couple of years of the likes of Glenn McGrath, Shane Warne, Justin Langer and Adam Gilchrist.
"I know how fierce Aussie competitiveness is," says Pietersen. "I played grade cricket in Sydney and even at that level it's incredible, so when they put on that baggy green cap and everything that entails, they'll come out fighting.
"We are going to come up against a formidable Australian team and there are areas in which we know we can improve."
Warne has gone as far as to say that a Pietersen-less England has no chance of Ashes success.
"England can't win if they don't have Kevin in their side," said the Australian legend. "They need him fit, they need him raring to go and hungry for success."
Pietersen, however, disagrees with his former Hampshire colleague and has backed his team-mates to cause the Australians all kinds of problems this summer.
"I thank Shane for saying what he did, it's very kind for a legend of the game to say that, but no one man can ever win a series against an Australian team," said Pietersen.
WHAT THEY SAY ABOUT KP
I expect Pietersen to rise to the occasion and cement his position as one of the great batsmen of the moment
"In our dressing-room, we've got guys there who - if we play well collectively - can beat Australia, but only together.
"All the batters have been scoring hundreds over the past six to nine months and Stuart Broad, James Anderson, Ryan Sidebottom and Graeme Swann have been superstars with the ball, so it's a collective thing.
"We know it's going to be difficult, but we have to get to grips with the series as soon as we can."
If there were any lingering doubts as to whether Pietersen is fully motivated for the challenges that lie ahead, he surely dispelled them with a typically forthright verbal volley in the direction of the summer's opponents.
"I hope the weather stays hot, because if it does, with Anderson, Broad and Flintoff bowling reverse-swing the way they do, I wouldn't want to face that," he claimed.
"The ball will certainly reverse-swing and we're going to be really tough to play against. I look forward to watching batters play it, the ball swinging both ways at 90mph."
The Australians have been warned: Kevin Pietersen is raring to go, and he is not about to take a backwards step.