It is clear to even the most uneducated cricket follower that Aaron Finch, for all his solidity on character grounds, lacks the technical skills to succeed consistently as a Test opening batsman against a good England attack in English conditions (or, for that matter, a good Indian attack in Australian conditions).

It is equally clear that Mitchell Marsh is no more a batting all-rounder than Patrick Cummins is. Therefore, the worst-case scenario for the selectors is that Finch and Marsh retain their positions for and after the Sydney Test match, make hay against a weak Sri Lankan attack that has been exposed not just in New Zealand but at home, and find themselves the incumbents for the first Ashes Test match at Edgbaston in August. Short-term retention might lead to long-term prolonged agony.

So Australia’s next three Test matches pose a conundrum with more complex consequences than merely winning and losing individual games. There must be a coherent plan. It is critical that some batsmen find confidence on the international stage, but equally critical that those batsmen not be the ones who cannot justify long-term investment.

Shaun Marsh continues to tease and frustrate. In the Melbourne Test match, he batted as well as anyone, and then got out, as he does, without prior warning. Marsh’s position in this series has been shored up by the absence of Steve Smith and David Warner. Just when the selectors might have preferred to wrap up the Shaun Marsh experience, his seven years in Test cricket made him suddenly indispensable.

By default, he retains his place for Sydney - but what if that leads to big runs against Sri Lanka? Does that mean he remains the incumbent when Smith returns to number four in the Ashes, and Australia is stuck with him for another Ashes?

The solution to this mess would have been the boldest course. The greatest risk now lies in the greatest conservatism. Australia, by sticking with what they know, risk getting stuck with what they know. Come the first Ashes Test, three of the top order will be Smith, Warner and Usman Khawaja. That means Australia need to find three other batsmen in the next three Test matches who can succeed in England. And for next week – and next month – they want to be picking batsmen who they unreservedly wish to score runs.

Marcus Harris and Travis Head are on the right track. Those two, and Khawaja, ought to be joined in Brisbane by a group drawn from Kurtis Patterson, Matthew Renshaw, Alex Doolan, Joe Burns and Jake Lehmann, with Cameron Bancroft and possibly Jason Sangha.

That is the project, but they are not quite ready to start it, and if all goes well in Sydney, all is in disarray for Birmingham. They have picked a batting line-up to save the furniture. The furniture is already gone. There are three Test matches left to trial genuine Ashes candidates, a Test trial in Test conditions, and there is no time to start like the present.