"Get hundreds" is the oldest line delivered by selectors to an unwanted batsman at the time of a squad announcement. It's also not always as simple a task as it appears.

Australia's coach Justin Langer declared Glenn Maxwell needed to become a more consistent century-maker if he is to figure in the Test team after his omission from the squad to face Pakistan, but a strange sequence of selection instructions and decisions appear to have made that harder than it otherwise might have been.

The omission of the 29-year-old Maxwell from the group to play two Tests against Pakistan was the headline choice made by Langer, the selection chairman Trevor Hohns and the national talent manager Greg Chappell. It was a decision forecast some weeks ago when Langer used an interview with the Australian to make an unflattering comparison between Maxwell and the suspended Steven Smith in terms of hundreds scored.

Maxwell will be "shattered" by omission Glenn Maxwell was expecting to be part of Australia's Test squad for the series against Pakistan according to Victoria team-mate Peter Siddle. Siddle, who was recalled after a gap of nearly two years, said that Maxwell will be "shattered" by his omission but backed him to respond in domestic cricket. "Coming home and being around him yesterday he was a little bit confident that he was going to be part of the squad so he'll be very disappointed," Siddle said. "You do feel for him, you always want your team-mates around the squad. I know he'll be shattered but I know he'll go out, work hard and push his claims for the summer."

"He's a really interesting one isn't he, Maxi," Langer said. "I think everyone including himself is trying to unlock the mystery of Glenn Maxwell. He knows it is completely up to him. He's [almost] 30 years old for example, Steve Smith's 29 and got 79 hundreds, Glenn Maxwell's got 17 hundreds [in all forms]. So an enormous talent, an elite fit young bloke, he's incredibly fit, he brings so much to the table.

"But maybe what he needs to learn ... in Zimbabwe he did that sign to me about watching the ball, ultimately that's what batting's about, learning the art of concentration. In my office at the moment I've got a letter from Sir Donald Bradman in 1995 where he talks about the most important thing is learning how to concentrate.

"What concentration means is eliminating all distractions and watching the ball like a hawk, over and over and over again. If you do that you get hundreds, and that's what the great players do. So Maxi that's his great challenge, that he becomes a more consistent player. He knows - anything I say is not going to surprise him - if he can keep learning to watch the ball really closely out of the hand for longer periods of time he'll get more hundreds, and then he'll be too good to ignore."

Langer more or less repeated these words in explaining on Tuesday why Maxwell was not included in the Test squad, despite a gaping hole left by Smith, David Warner and Cameron Bancroft, and despite his strong showings for Victoria in the Sheffield Shield last summer, where he tallied 707 runs at 50.50, including one innings of 278 against New South Wales.

"He's a very good player and I was very impressed with him in England, the way he goes about his business," Langer said. "I'd love to see Maxi score more hundreds. And he and I have talked a lot in our brief time together about the art of concentration and watching the ball like a hawk and I'm sure if he does that more regularly, he will be making a lot more hundreds and be much more pickable for Test cricket."

This all seems straightforward enough. But ESPNcricinfo has learned of a somewhat confusing sequence for Maxwell around the aforementioned tour of England and Zimbabwe, where he performed below expectations in the limited-overs team - following on from another subpar display for Delhi Daredevils, under the mentorship of Ricky Ponting, in the IPL. Those displays left Maxwell eager to spend more time in the middle, potentially via a white-ball deal in English county cricket that could then have grown into a red-ball stint, as previously done by Finch, for Yorkshire, among others.

"At a time when the batting-talent cupboard is all but bare for Australia, Maxwell's omission seems a greater gamble than his inclusion would have been"

However it is believed he was counselled by Cricket Australia to rest-up ahead of the Australia A tour of India rather than playing elsewhere. This advice then led to an understandable sense of mystification when the squad was announced and Maxwell's name was omitted. At the time it was explained that Maxwell was one of several players deemed to have played and succeeded often enough in Asian conditions to not need the stint in India, a line that Langer also followed in his aforementioned interview.

When asked why Maxwell wasn't then going to India to play long-form matches for Australia A where he could work on his concentration levels, Langer replied that the Victorian's qualities against spin were already well understood by the selectors. "I think we aren't taking him to India because we've seen he's 30 years old now," Langer said.

"I know we're taking Ussie [Usman Khawaja], but there's different reasons for that, a lot of discussion that he can't play spin bowling and I just don't believe that, but a good opportunity for Ussie to get some confidence up against spin. Maxi, we're not taking Aaron Finch either, we're not taking Shaun Marsh, they've had some time in India, we wanted to give others opportunities."

So it appeared at the time that Maxwell was still in contention to be part of the Test squad to go to the UAE, but with a more tenuous grasp on a touring berth than he might otherwise have thought. What happened in between, however, was the scoring of runs by Khawaja, Travis Head and also Marnus Labuschagne in the first of Australia A's two first-class matches. This was seemingly enough to squeeze them all ahead of Maxwell in the Test-match reckoning. Shaun and Mitchell Marsh and Finch were all apparently inked into the UAE squad beforehand, as Langer indicated. So Maxwell had been asked to make more big scores, then been dropped because others were given the chance to do so ahead of him.

"I'm really thrilled for Aaron Finch. One thing we ask of our players is to perform and in white-ball cricket he's as in-form a player as there is in the world at the moment," Langer said. "What I know about Aaron Finch is he scores hundreds and in Test cricket that's very important. You've got to score hundreds. And he's also one of the core leaders in the group and to have him in the squad, I know he's waited a long time for it. Hopefully like a Mike Hussey or a George Bailey or a Chris Rogers he can have an impact on Test cricket as well as white-ball cricket.

"Marnus Labuschagne, he's like Cameron Bancroft in the fact that he would literally do anything to play cricket for Australia. He loves playing cricket. His work ethic is as good as anyone. From everything I know about him - I've only met him a couple of times, but everything I'm hearing about him on the Australia A tour and for Queensland - he's one of those guys who is like the heartbeat of the team, like a Cameron Bancroft in terms of work ethic, desire, focus. So he's another great person to have in the squad."

These glowing character references will of course lead to other questions about Maxwell, in terms of whether the current Australian set-up considers him the sort of cricketer around whom to build a new team. His under-performance in England, when among the most experienced members of the ODI batting order, cannot have helped build an impression of reliability. But at a time when the batting-talent cupboard is all but bare for Australia, Maxwell's omission seems a still greater gamble than his inclusion would have been.

No longer consumed by thoughts of resuming his Test-match career against Pakistan, Maxwell will now turn out for Victoria in 50-over and Sheffield Shield competitions. Runs in domestic ranks this summer may well lead to the moment when Maxwell and others find out whether that "get more hundreds" line is genuine, or just a way of letting him down gently about his services not being required.