Veteran defender Lucas Neill on Monday retained the skipper's armband for Australia's friendly against Costa Rica despite widespread speculation that Tim Cahill would take over under new coach Ange Postecoglou.

Neill, 35, has been under pressure following successive 6-0 thrashings in Brazil and France that led to coach Holger Osieck being fired, with reports suggesting his successor would opt for a fresh start.

But Postecoglou kept faith with his captain for Tuesday's clash despite making clear when he took over last month that the ageing core of the Socceroos squad was on notice in the lead-up to next year's FIFA World Cup™.

"Lucas will be starting and will skipper the side tomorrow night," Postecoglou said. "There wasn't a decision to be made as far as I'm concerned."

Neill, who has been capped 95 times and played every game in Australia's 2014 FIFA World Cup campaign, vowed to repay the faith as he prepares to lead his country for a record 61st time in Sydney on Tuesday.

"I believe in myself," Neill told reporters. "Football has to do the talking.

"Right now, there is nothing else I want to concentrate on other than tomorrow night because it's vital for the manager to get off to a good start, and it's vital for me.

"I have to perform and perform well and justify my selection. From there, we can start looking at the future."