The Danes could put themselves on the verge of qualification for the knockout stage with a second Group C victory in Samara on Thursday after a 1-0 win over Peru.
The Socceroos, meanwhile, went down 2-1 against France in Kazan, so are fighting to keep their World Cup hopes alive.
With so much on the line, much has been made of just how Australia will look to shackle the creativity of Eriksen, who netted a hat-trick as Denmark beat the Republic of Ireland 5-1 in their qualifying play-off second leg in Dublin.
Hareide, though, has no doubts the Spurs man will be ready for the challenge.
“Christian is a player who can change matches, and we try to get him involved as much as we can,” the Norwegian head coach told a press conference, broadcast on the official FIFA tournament website.
“The opponents, they are going to be very cautious and careful about him, but he is used to that isn’t he from the Premier League?
“We have seen in the Premier League that he can succeed nevertheless.
“We hope that we will get him up to a good level and that he will be able to show good things at this World Cup.”
Australia coach Bert van Marwijk will not need to do any extra homework on Denmark’s star man, Eriksen having worked his way up through the Ajax youth system.
“I know Eriksen, because I already saw him in Holland and also a lot of time in Tottenham,” said the Dutchman, who guided his nation to the 2010 World Cup final where they lost to Spain.
Norway will be without midfielder William Kvist, who broke two ribs against Peru.
Leicester goalkeeper Kasper Schmeichel is expecting another stern test against the Australians.
“When you reach this level, all teams are well prepared, so mentally you have to be ready to fight for it, because small margins will make a difference at this level,” he said.
Van Marwijk also knows the size of the challenge awaiting his side at the Samara Arena.
“The Danes are a strong team, they are number 12 in the world rankings, that says enough,” van Marwijk said.
“We played against France, they have more quality in the players and more creativity, but I think the Danish are more of a team.
“We have to give the same performance against France, with a lot of discipline, but improve in the things which can make a difference.
“We just need to look at the details. We have to play and get more chances. Everything we did, we have to do it better.”
La Roja were given a tough fight by Carlos Queiroz’s men, and things remained goalless at half-time.
Costa’s goal came in the 54th minute, and while Iran did manage to get one back, it was disallowed by the referee due to Saeid Ezatolahi being offside.
Here we take a look at player ratings for Fernando Hierro’s Spanish side.
David de Gea – 5: Had little to do but still managed to look shaky. A real worry for Spain heading into the latter stages.
Dani Carvajal – 7: Returned to action following injury and always looking to advance down the right wing. Looks fully fit which is great news for Spain.
Gerard Pique – 6: Little defending required but was occasionally troubled by the physicality of opposing striker Azmoun. Below his best.
Sergio Ramos – 7: Defended with stern determination and sent an ambitious long-range free-kick into the wall as his team pushed for the opener.
Jordi Alba – 6: Struggled to make an attacking impact in the tight spaces of Iran’s penalty box but defended with diligence.
David Silva – 8: Always probing from the centre of the pitch and a regular goal threat, hooking one shot over the bar and having another blocked.
Sergi Busquets – 7: More advanced than usual as Iran sat back and had a rare long-range strike saved. Took control after the opener.
Isco – 8: Took the lead role in Spain’s attempts to break down Iran and produced some spectacular touches, always looking his team’s most creative force.
Lucas Vazquez – 5: Selected to give penetration down the right wing but failed to do so. Replaced by Asensio after a disappointing display.
Diego Costa – 6: Desperately struggled to get involved in the first half but was in the right place to break the deadlock with a flukey deflection.
Andres Iniesta – 6: Very quiet until he sparked the opening goal with a classy dribble. Replaced shortly after having done his job.
Koke – 6: The first introduction, replacing Iniesta in midfield, and shored things up in the middle.
Marco Asensio – 5: Played down the right wing in the latter stages but failed to make much impact.
Rodrigo – 6: Introduced for the final few minutes, with little chance to impress.
Spain managed to edge past Iran with a 1-0 win in a World Cup Group B encounter at the Kazan Arena on Wednesday.
Diego Costa scored the only goal of the game when the ball was hit onto his shin before nestling in the back of the net in the 54th minute.
While the Spaniards dominated possession, it was Iran that looked the more threatening in the closing stages and had to be kept at bay.
Goals – 1
Shots – 18
Possession – 79%
Tackles – 8
Dribbles – 21
Hierro set up his side in what looked like a 4-2-3-1 with Andres Iniesta alongside Sergio Busquets while Isco, David Silva and Lucas Vazquez made up the three behind front man Diego Costa.
Iniesta, however, operated further forward with Spain dominating possession, leaving Sergio Ramos to step up from the defensive line and support Busquets in central midfield, leading the duo to make the second and third most passes in the game (99 and 97) behind Isco (103).
TACTICAL TALKING POINT
Lack of genuine width
Koke dropped out of the XI that faced Portugal with Vazquez coming in instead. The Real Madrid winger was presumably expected to provide some width down the right side and help stretch the Iranian defence but he had a disappointing outing.
He gave the ball away more than any other Spain player and got sucked into central areas. When he did get wide, his crosses (4) failed to find a team-mate. The full-backs did act as auxiliary wingers but the ball wasn’t zipped into them with any urgency. Spain dwelled on possession through the middle and seemed only to play it wide when short of options in the centre. The lack of aerial threat from open play didn’t help matters.
His side did dominate play but were fortunate with the goal. Hierro seemed reluctant to make changes to alter the course of the game. Marco Asensio only came on with 10 minutes to play when they could’ve used his pace and direct running to create inroads that their intricate passing could not, and pull players out of position.
Rating – 5/10