Having reverted to a traditional back four, Socceroos coach Bert van Marwijk has included several defenders in his World Cup squad for Russia.
Goal examines the Socceroos defensive options...
1. Trent Sainsbury (Jiangsu Suning)
He didn't play in the 2014 World Cup because of injury, but Trent Sainsbury has quickly established himself as a key player for the Socceroos.
The centre back was recently handed the captain's armband against Czech Republic and will be one of the first names on the team sheet for the World Cup.
At 26, Sainsbury's best years as a defender are arguably still ahead of him but he's already proven his quality and even secured a loan to Inter in 2017.
While getting just one game with the Italian giants, he has since enjoyed a successful stint in Switzerland with Grasshopper where he was quickly appointed captain and even deployed as a holding midfielder.
After playing a big part in Australia's qualification campaign, only injury will stop Sainsbury playing an even bigger part in the Socceroos World Cup adventure.
2. Aziz Behich (Bursaspor)
After a strong season in Turkey with Bursaspor, left back Aziz Behich has quickly made that spot his own for the Socceroos.
The 27-year-old bagged five goals across 31 appearances for Bursapor, demonstrating his threat in attack with his pace set to be particularly crucial for an Australian outfit looking to play on the counter.
Behich has played every minute under van Marwijk to date and don't expect him to miss many any time soon.
With a headache in France looming first up for Australia, Behich also has some crucial inside knowledge of the opposition, considering he plays club football with Kylian Mbappé's brother Jirès.
3. Josh Risdon (Western Sydney Wanderers)
Locked in a battle for the right back spot ahead of the Socceroos 4-0 friendly win against Czech Republic, Risdon barely put a foot wrong to secure his spot on the plane to Russia.
Risdon is in career best shape after a season in Western Sydney and like Behich, will offer Australia a real outlet moving forward.
His link-up play with right winger Mathew Leckie was also looking promising against the Czechs, making Risdon a potentially crucial cog in this Socceroos machine.
Though with just seven caps to his name, Risdon looks more than ready to tackle Russia head on and van Marwijk has certainly backed him by axing possible back-ups Fran Karacic and Josh Brillante from the squad.
4. Mark Milligan (Al Ahli)
While a definite question mark over his place in the starting back four, Milligan's experience and versatility makes him a very valuable defensive option.
Milligan started as a centre back against Czech Republic and Hungary but didn't put in the best performances, suggesting his spot could be up for grabs.
Regardless of whether he starts or not, the fact Milligan is entering his fourth World Cup makes his simple presence in the squad worthwhile.
Being right footed, Milligan could also provide cover for Risdon out wide and even move into midfield if needed.
Despite being 32, age is no issue for the former Melbourne Victory skipper either, after he earned a million-dollar move to Saudi Arabia mid-season with Al Ahli.
5. Mile Jedinak (Aston Villa)
He might be recognised as a midfielder, but Socceroos skipper Mile Jedinak could loom as the perfect piece for Australia's defensive puzzle.
Sitting out Australia's most recent friendly, the green and gold midfield shined with two ex-Socceroos suggesting Jedinak can't be brought back in to destabilise it.
As such, a move to the back could be an appealing alternative for van Marwijk with Jedinak often playing there for club side Aston Villa.
Having arrived late in camp as Villa lost a promotion play-off, Jedinak revealed the Socceroos coach has been deploying him as both a midfielder and defender.
While it might not be his most-suited position, the skipper's presence on the pitch, wherever that may be, can't be underestimated - as he showed all too well with his hat-trick against Honduras.
6. Milos Degenek (Yokohama F.Marinos)
Now playing under former Socceroos coach Ange Postecoglou in Japan for Yokohama F.Marinos, Degenek is a versatile defender showing a new-found ability in front of goal.
Degenek found the back of the net three times for Yokohama inside a month leading up to the World Cup and even forced an own goal against Czech Republic.
Generally deployed as a centre back, Degenek replaced Risdon at right back for that clash and looked solid in a brief cameo.
The 24-year-old already has 18 caps to his name and has rarely looked out of depth on the national arena.
7. Matthew Jurman (Suwon Bluewings)
A late Socceroos bloomer, 28-year-old Jurman was handed his international debut last year under Ange Postecoglou and didn't look out of place in crunch play-off matches.
Injury however meant he didn't get to play across two friendlies in March under van Marwijk, and while fit again, didn't see any action against the Czechs.
His inclusion in van Marwijk's first squad despite injury suggested Jurman would be key to the Dutchman's plans but it remains to be seen if that is still the case.
What, if any, involvement he gets in a final friendly against Hungary will be telling for Jurman as the one-time A-League reject makes his trip to Russia.
8. James Meredith (Millwall)
Much like Jurman, Meredith has left it late playing for Australia having made his debut in 2015 as a then 27-year-old.
Three years on, the Millwall left back still only has two caps to his name and is yet to see any action under van Marwijk.
Despite a stellar club season with Millwall, who did make a surprise push for promotion, Meredith remains stuck on the Socceroos fringes and with Behich locked in at left back, that's where it looks like he'll remain in Russia.
Meredith could still prove handy off the bench with his physicality in particular a potentially attractive attribute to utilise against the likes of France and Peru.