Watching the game alongside then-Scotland coach Craig Brown, I asked what he thought of the way South Melbourne were set up with three centre backs?
“The problem,” he replied, “is that all three of them can be taken out with one pass” – as happened when Cameroon scored their goal against Postecoglu’s Socceroos on Thursday (Friday AEST).
Alternatively they can be outflanked. The idea behind the three centre backs is to be able to pack midfield and play a compact passing game.
But an opponent who moves the ball quickly can get in the space behind the wing backs.
Earlier this month it took Brazil just twelve seconds to break down the right and take the lead.
In the Socceroos' Confederations Cup opener, Germany needed all of four minutes to do the same.
For the Cameroon game Alex Gersbach replaced Aziz Behich, but it made little difference. The African champions were continually able to get into that space.
A stream of chances came from that flank, and had centre forward Vincent Aboubakar been on form then Australia would already have no chance of making the tournament's semi finals.
They now have to beat Chile – but the problem here is that the Chileans are strong in the very area where the Socceroos are weak.
Over the last ten years, under a succession of Argentine coaches, Chile have worked on a bold style of play that makes them fascinating to watch.
One of the base ideas is that in a side that wants to attack the conventional full back is a waste of a player.
Chile look to push both full backs high into the opposing half at the same time – and they then look to bring them into the game, opening up the play with long diagonal passes in their direction, creating two against one situations down the wings and aiming to make the ball fizz with rapid passing moves.
The objective it to gain numerical superiority in that part of the pitch where they want the game to take place – the opponent’s half.
When Chile are in possession, the man on the ball should have plenty of options for a quick pass. When the move breaks down they seek to swarm around the ball and stop the counter-attack at source, suffocating the opponent close to their own goal.
This, then, is the problem of Australia’s wing backs dropping deep.
The Socceroos then face the risk of defending with a line of five – and without a great deal of attacking pace, this could leave them permanently on the back foot, in a game that they need to win.
But there is hope.
Playing the Chile way requires high intensity and constant movement. Keeping this up for the duration of the match is too much to ask of the current side, who have been together for almost a decade.
The heart of the Chile side came through the team that finished third in the 2007 Under-20 World Cup – the ever inventive and elusive Alexis Sanchez, who against Germany became his country’s all-time top scorer; attacking midfield powerhouse Arturo Vidal; defensive pit bull Gary Medel; rampaging attacking right back Mauricio Isla.
Others – centre back Gonzalo Jara, left back Jean Beausejour, key central midfield organiser Marcelo Diaz – are even older. This is a side that is ageing together.
Assuming they qualify, Russia 2018 will be the third and final World Cup for Chile’s golden generation. And what they have acquired in experience and self-esteem they may well have lost in lung power. The evidence is certainly pointing that way.
Chile have played four matches on their current European adventure – warm up friendlies against Russia (1-1) and Romania (2-3) before their Confederations Cup clashes with Cameroon (2-0) and Germany (1-1).
On every occasion they took the lead, getting off to a sequence of exhilarating starts. But the scorelines show just one victory, and this would not seem to be a coincidence.
Chile now seem unable to maintain their pressing game for the full 90 minutes.
There are two problems. The first was demonstrated by Germany’s equaliser; the attempt to press with tired legs can leave the team stretched out.
Approaching half time the Chileans were unable to maintain their stranglehold on the Germans, and Emre Can broke away with plenty of space to open up their defence. He slipped overlapping left back Jonas Hector, whose low cross was turned in from close range by centre forward Lars Stindl.
Can Australia come up with something similar as Sunday’s game wears on and space opens up? Perhaps, though the lack of speed in the final third is a concern.
But they might have more success exposing another flaw in the South American champions’ defence.
There is little height in Chile’s back line. They have worked at dealing with set pieces played high into their box, but they can still be caught out.
Two weeks ago Russia’s equaliser against them came from a corner, met by a towering header from centre back Viktor Vasin.
Here Australia can surely do some damage. If Aaron Mooy’s set piece delivery is on target, then, the defenders or Tomi Juric could cause some damage – or maybe there could be a happy ending to Tim Cahill’s 100th game in Australia colours.