The Socceroos's clash with Croatia will be a dress rehearsal for their World Cup opener against Chile but coach Ange Postecoglou is also wary of giving too much away.

Australia face a stern test against world No 20 Croatia in their final hit-out in Salvador, Brazil, on Saturday, a week before kicking off their World Cup campaign against Chile.

Postecoglou says he'll field close to his full-strength side but indicated some tactical plans would be kept under wraps.

"I'm also mindful to surprise the opposition in the first game, that will help not to reveal our whole hand," he said.

World Cup 2014

Postecoglou confirmed Tim Cahill and skipper Mile Jedinak, back from his groin injury, would play against Croatia and the coach fielded what looks set to be his starting 11 in a training game on Thursday.

Cahill was deployed at the point of attack, with Tommy Oar in a new role as the playmaker.

Oar has played almost exclusively as a left winger for the Socceroos, but he played much of the recent season at his Dutch club as an attacking midfielder through the centre.

Matthew Leckie was switched to the left wing with Ben Halloran on the right, while Jedinak and Mark Milligan occupied the holding midfield roles.

Creative midfielder Mark Bresciano would normally feature in the full-strength side but the veteran is still plagued by a back injury and was again consigned to light duties with doubts he will be ready for the Chile match.

Mat Ryan is in goal, while Postecoglou appears to have settled on Alex Wilkinson as Matthew Spiranovic's partner in the centre of defence.

Ivan Franjic rejoined team training for the first time since injuring his knee in the farewell game against South Africa on May 26 and was back in his right-back role, with Jason Davidson on the left.

The team combination seemed to suit Cahill, who scored twice in Thursday's training game.

The striker, who has netted four times in Australia's last three matches - against Costa Rica, Ecuador and South Africa - says it's important his teammates know they can count on his finishing.

"I want to keep my training to a high intensity so that come the Chile game the boys will know that once we are over that white line that I am going to give everything," he said.

"In the last three games I played I have been leading from the front, scoring three goals in four games and really trying to have an impact."

Cahill recalled Australia's 2-2 draw with Croatia in 2006 that sealed their passage to the second round of the World Cup as one of "the proudest moments Australian football".

It will be a vastly different Croatia side they will meet on Saturday but with stars like Real Madrid midfielder Luka Modric, they will be just as difficult.

AAP