For Michael Clarke, the next three weeks are quite straight forward: win a couple of coin tosses, make a couple of hundreds, retain the Ashes, retire from Test cricket with grace and dignity.

If anyone needs the captain, he will be in his trailer with Warnie, or the Channel Nine commentary box.

If only it was that simple.

In between winning and losing Test matches, and two-hour net sessions as he fights to save his career, Clarke is also penning another of his Ashes tour diaries.

The belief is he won't be holding back in this instalment as his time in international cricket draws to a close.

There are only two chapters left to write, at Trent Bridge for the fourth Test and then the Oval for the fifth, and they should be as intriguing – presumably – as the lengthy passage about Brad Haddin's confusing axing and whether Clarke endorsed it.

Clarke is often described by even his closest allies as a "control freak" but right now he has negligible influence or authority over how this battle for the urn is playing out.

Even at this delicate stage, it would be reckless to write off him and his team. But even his closest supporter, Shane Warne, has cast doubt on his future beyond the Ashes.

Clarke's issues extend beyond his batting. His choices as captain, without hardened, experienced heads like Haddin and Shane Watson next to him in the middle, are being questioned like never before.

But it's with the willow that he desperately needs to turn the beat around. It's a familiar plotline.

Michael Clarke's year from hell. Photo: Reuters

The hounds were released on Mark Taylor in 1997, so lean had his run-scoring been for 18 months. The English press presented him with a metre-wide bat upon his arrival in the UK. Then he scored a gritty 129 at Edgbaston, resuscitating his career.

Six years later, Steve Waugh set a new standard for saving Test match careers with his fabled last-ball century against England at the SCG. Stewards delayed the start of a horse race in country Victoria as the skipper hunted down triple figures before stumps, just so the jockeys could hear it.

Waugh will tell you there must've been a crowd of at least 100,000 at the SCG that afternoon, given how many have pumped his hand in subsequent years and assured him, "I was there, Tugger! I was!"

These inspiring moments have furthered the legend of the baggy green, and made for endless hours of television montages in slow motion, accompanied by John Williamson songs.

Having scored 8605 Test runs at 49.73, including 28 centuries, in 122 matches, Clarke has done more than his bit, too, at enhancing that legend.

In the last two years, he was won many hearts among fans that had previously thought of him as nothing more than a pop-star captain.

His unbeaten 161 in Cape Town against South Africa with a broken shoulder, and then his courageous 128 in Adelaide weeks after the death of Phillip Hughes, finally convinced his critics that he was a player of substance.

For years, Clarke was privately tortured about his portrayal in the media and the public's dislike of him. Adam Goodes has been booed by rival fans. Clarke was booed by his own country.

The rebuilding of his public identity in the past 18 months, especially in the wake of the last Ashes series defeat on English soil, has been remarkable.

Nevertheless, the ending of his Test career threatens to become messy.

He could bump himself back down the order to No. 5, just like Waugh, and wring out every last second as Australian captain.

His supporters will point to the scarcity of middle-order talent that would take his place. Are Usman Khawaja or Joe Burns the answer? They might have to be.

Cricket is a sport obsessed with numbers, but Clarke's skinny returns since last summer don't really tell the story. His face does.

Maybe I'm reading into too much. Maybe I've known Clarke and covered his career too long. Maybe it's obvious. But his expression with each cheap dismissal is undeniable: it is a blank expression of utter bewilderment. He isn't annoyed but lost.

Michael Clarke's career is at the crossroads.

There are other clues, too.

Some are saying the delivery from England paceman Steven Finn in the first innings at Edgbaston was almost unplayable. Let's be honest: it was a decent, full delivery.

Clarke dabbed at it late, playing over the top of it. In his pomp, it would never have troubled him. He suddenly looked every day of his 34 years.

The other hint came in the form of his vicious self-assessment following the eight-wicket loss.

"I am more concerned about my form," Clarke said. "When you bat at No. 4 in an international cricket team you have to make sure you lead the way and make runs. If I make runs I am sure Vogesy [Adam Voges] will follow. I think it's always going to be hard to beat any opposition when they've got 11 and we've got only 10."

Those remarks sounded more like a concession than brutal self-appraisal. Clarke has for years danced around questions about his team and own form better than any politician trying to explain their travel expenses. But this was candour he has rarely displayed.

Pressed on whether this series would be his last, he was emphatic: "Not at all".

Without injured fast bowler Jimmy Anderson and given their own erratic form line, you could hardly put the farm on England nailing Australia in the next two Tests.

A chaotic end for Australia, however, threatens to prise open all sorts of wounds between Clarke and those above him. Their relationship was almost ruined beyond repair in the lead-up to the World Cup – despite denials from all concerned.

But if coach Darren Lehmann and chairman of selectors Rod Marsh botched Haddin's dumping, upsetting team morale, what is looming with Clarke?

The captain can take the decision away from them.

A final hurrah during the Australian summer would be firmly in his mind, playing his farewell Test at his spiritual home of the SCG.

But Clarke should retire at the end of this series. He can go out on his terms, writing the final chapters of his career as he sees fit. There would be no shame in it.