The 33-year-old defender was handed the captain's armband for last month's 4-0 win over Kuwait, which marked Australia's first game since Jedinak's decision to step down.

Arnold had previously indicated he would rotate around the captaincy in the lead-up to the 2019 Asian Cup.

The Socceroos have arrived for their final camp before the Asian Cup in January, with friendlies against Korea Republic and Lebanon this week.

Milligan skippered his Scottish club Hibernian on the weekend and seems the logical choice, although gaining the job permanently may hinge on his international plans beyond the Asian Cup.

Arnie’s son-in-law Trent Sainsbury, 26, appears Milligan's only genuine contender for the permanent Australian captaincy after he wore the armband for the World Cup warm ups.

But the Hibernian man said he remained uncertain about Arnold's thinking.

"I'm really not sure," Milligan said. "That's something that we'll leave to the boss.

"We're focusing on what we have to do individually and as a unit. He's made it pretty clear when he's ready to make a decision, he'll make the decision."

The dearth of options follows the international retirements of Jedinak and Tim Cahill, who combined for almost 200 caps.

Robbie Kruse, Mathew Leckie, Mat Ryan, Tomi Juric, Tom Rogic and Aaron Mooy are Australia's most capped current players beyond Milligan and Sainsbury.