The Danes haven't lost in 16 straight matches and haven't conceded in their past five games either, but the red and white weren't very convincing in a 1-0 win over Peru.
As such, the Socceroos are capable of pulling off an upset and keeping their hopes of progression to the round of 16 very much alive.
At the heart of any potential victory will be the starting side Bert van Marwijk selects and former Sydney FC assistant coach Phil Moss believes there are a number of big changes that need to be made.
"I would bring Matt Jurman in at left stopper," Moss told Big Sports Breakfast.
"I'd push either Milligan into midfield next Jedinak or bring Luongo in.
"I'd push Aaron Mooy further up into number 10 and I'd start Timmy Cahill."
As far as shake-ups come, it would certainly be a massive one and for Dutch coach van Marwijk, he's extremely unlikely to want to tinker so much with a side that only lost 2-1 France.
While a strong performance against the French, a more positive result is a must against Denmark with Daniel Arzani and Cahill two names linked to achieving exactly that.
Former Socceroo Mark Bosnich believes Arzani, who is the youngest player at the World Cup, should start with Cahill coming on off the bench.
"I would start with Daniel Arzani,” Bosnich told SEN.
"The other day, Robbie Kruse put in a good shift defensively but from an attacking point of view offered us nothing.
"Daniel Arzani is a player who offers something completely different that we haven’t got."
Whatever the Socceroos starting 11, it's clear that every single player must be at their best if Australia hope to defeat Denmark.