Two Hyundai A-League options battle to fix Australia's 'problem position'

Bert van Marwijk's honest admission of uncertainty over the Caltex Socceroos' right-back spot has written the first chapter in what looms as one of the team's most fascinating FIFA World Cup plotlines.

The experienced Dutchman drafted uncapped newcomer Fran Karacic into a preliminary 32-man squad, announced on Monday, as he searches far and wide for the perfect answer to a position that has seen candidates come and go.

READ: How unknown gem Karacic was unearthed for Caltex Socceroos

Karacic, a Croatia Under-21 international, now appears locked in a four-way battle with Western Sydney Wanderers' Josh Risdon, Sydney FC's Josh Brillante and Bailey Wright to start on the right side of defence in Russia.

Risdon had looked to have pushed himself to the front of the queue with an assured performance in the recent 0-0 friendly draw against Colombia in London.

Now faced with the prospect of fresh contenders, the Western Sydney Wanderers man is unfazed by the selection scrutiny that comes with major tournaments.

"It's up for grabs," Risdon acknowledged. "Being an out-and-out right-back myself, it's a great opportunity.

"There are a few candidates for that spot but I'm excited for the challenge."

WATCH: One-on-one with Josh Risdon

Risdon's chance in the second of the two March friendlies come on the back of a difficult night out for Bailey Wright in the loss to Norway.

The Bristol City captain could yet win back the spot, but figuring in his more natural position in the heart of defence seems likely for the Caltex Socceroos regular.

Bailey Wright
Bailey Wright is among the players vying for a place in the 23.

Should that be the case, there could be another reliable utility player finding a new path into the starting XI.

Sydney FC star Brillante - who narrowly missed out on selection in 2014 - was mentioned by Van Marwijk as a genuine option for the sought-after role.

Though his return to national team reckoning has been built on indefatigable efforts in the Sky Blues' engine room, the ex-Fiorentina player does boast know-how at the back and is willing to take on any task.

WATCH: One-on-one with Josh Brillante

"I'm honoured as always to be included in the national team," the 25-year-old said.

"It's going to make things a little bit difficult for me – for the last few seasons I've been playing in midfield but I have played right-back in the past.

"It will be exciting going into camp. Having a position like that, a chance to make it yours and cement your spot is massive going into a tournament like this."