Ange Postecoglou's new-look Socceroos are likely to be tested to the limit when their World Cup campaign begins against Chile on Friday.
The Group B clash in Cuiaba, which kicks off at 8am on Saturday morning AEST, is Australia's first competitive fixture under Postecoglou, whose tenure has produced one win, one draw and two losses from four friendlies to date.
The former Brisbane Roar and Melbourne Victory coach was hired by Football Federation Australia to replace Holger Osieck in October, the German who qualified the team for the World Cup having been sacked following successive 6-0 thrashings to Brazil and France in friendlies late last year.
The new man was charged with leading a long overdue regeneration of the national team and he has acted aggressively within that remit, taking an inexperienced squad to Brazil, where the Socceroos face 'mission impossible' against Chile, beaten 2010 finalists the Netherlands and world champions Spain.
Chile coach Jorge Sampaoli has continued the good work done by Marcelo Bielsa in charge of La Roja, who are expected to employ an energetic, pressing style against Australia with a high defensive line.
The Socceroos hope to exploit the adventurous approach of their opponents at the Arena Pantanal by getting in behind the Chile backline. The pace of Tommy Oar and Mathew Leckie combined with the aerial prowess of veteran forward Tim Cahill are the most likely routes to goal for Australia.
But can an inexperienced defence, with Alex Wilkinson - very much a late bloomer in international football with just three caps at the age of 29 - cope with the pace and movement of Chile's versatile attack?
Postecoglou will have a decision to make on the fitness of Mark Bresciano, who has been nursing a back problem in the lead-up to the tournament but came on as a substitute in the 1-0 friendly loss to Croatia last weekend. If he does play, the 34-year-old is likely to shield the defence and create from deep, with Mile Jedinak and Mark Milligan doing the hard running ahead of him.
Chile have a more serious injury concern. Star man Arturo Vidal has failed to recover as quickly as expected from minor knee surgery and is reportedly unlikely to play on Friday. Without or without Vidal, Barcelona forward Alexis Sanchez will pose an enormous threat to the Socceroos' largely untested defence.
If Chile fail to beat Australia they will have the unenviable task of seeking to pick up maximum points against one or both of the Netherlands and Spain. The Socceroos though would consider a point an enormous achievement and give them confidence ahead of two equally daunting matches.
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