Denmark will "struggle" if Australia can stop Christian Eriksen at the World Cup and William Kvist's injury is a blow, according to Michael Jakobsen.
Eriksen is undoubtedly his nation's key player and the Tottenham star set up Yussuf Poulsen's goal in his side's 1-0 win over Peru in their Group C opener.
The 26-year-old is set to again shape as a threat when Denmark face the Socceroos in Samara on Thursday.
Jakobsen, a former Denmark international now playing for Adelaide United, said stopping Eriksen would be vital for Australia.
"If they can eliminate him from the game, Denmark will struggle," he told Omnisport.
"He is the key to the majority of the offensive part."
Jakobsen also pinpointed Pione Sisto as a key for Denmark, saying the Celta Vigo attacker could be a "massive threat".
However, Jakobsen noted that the loss of midfielder Kvist – who broke his ribs against Peru – is a hindrance to how Denmark want to play.
"They don't have anybody who can go into that position and fill it like he does," the five-time Denmark international said, having suggested Chelsea defender Andreas Christensen could move into midfield.
"He's not the best with the ball and he plays a lot backwards and sideways, but in the defensive organisation, he's very good to cover the back line."
Jakobsen believes France – who beat Australia 2-1 in their opening game – will win all three of their group matches.
As for whether Denmark would finish second, the 32-year-old said: "I was convinced before the tournament started, but I'm not that convinced anymore."
20. September 2018
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|Pandya, Axar and Thakur out of Asia Cup|
|England omit Cipriani, Tuilagi and Ashton called up|
|Can reacts to Ronaldo´s red card: We are not women|
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|Shy Osaka not comfortable with new-found fame|
|Belgium and World Cup winners France make FIFA rankings history|
|Ronaldo wanted to impress - Bernardeschi sympathises after Juve superstar´s red|
|Van Dijk warns Liverpool: Believe we can win trophies or stay home|
|Menezes complains of anti-Brazilian conspiracy after Dede´s VAR red|
|Diamondbacks rout Cubs to remain in postseason picture|
|Modric embraces Ballon d´Or chants as Di Francesco backs Madrid star for award|
|MLS Review: Martinez helps Atlanta stage comeback amid VAR controversy|
|Kerevi recommits to Wallabies, Reds|
|Lyon to ban fan for life after footage of Nazi salute emerges|
|Milan must respect opponents – Gattuso not underestimating Dudelange|
|Copa Libertadores Review: Zarate leads Boca, River draw|
|Mourinho: Dalot can play at Man United for more than 10 years|
|Johnson hoping to erase East Lake demons|
|´No question´ Fitzgerald faces Bears, says Cardinals´ Wilks|
|Rodgers says roughing the passer penalties are ´going the wrong direction´|
|Ravens fined $200,000 for violating communication policy|
|LeBron James set to star in ´Space Jam´ sequel|
|Ronaldo red card ´absurd´, says Pjanic|
|Kovac hails ´special´ Sanches after Bayern goal|
|Marcelino: Tearful Ronaldo said he did nothing wrong|
|Fernandinho takes blame for Man City´s Lyon loss|
|Lovren denies any wrongdoing after perjury charge|
|Plzen boss Vrba slams late mistakes|
|I almost scored as many as Messi - Tagliafico the unlikely hero for Ajax|
|Ronaldo deserves Ballon d´Or not Modric, says Casemiro|
|United fan Rafael - I´ve never lost at City|
|Davis explains abrupt mid-game NFL retirement: ´Football is not for me´|
|Lopes pays tribute to under-fire Lyon coach Genesio|
|Toulon´s Bastareaud handed five-week ban|
|Steelers WR Brown disciplined for missing meeting|
|Arteta refuses to make excuses for Manchester City´s Lyon loss|
|Allegri calls for VAR after Ronaldo´s contentious red card|
|Championship Review: Boro go second, Birmingham still winless|
|Lopetegui: Mariano took his chance|
|Juventus proved their quality after Ronaldo red card - Bonucci|
|Pogba ´class´ impresses Mourinho|
19. September 2018
|Man City not Champions League favourites, insists Bernardo Silva|
|Isco calls for Modric to win Ballon d´Or after Champions League win|
|Wawrinka into last eight in St Petersburg|
|Goal hero Pogba is one of the best in the world - Shaw|
|Sane SOS can´t salvage sorry City display|
|Hoffenheim will learn lessons from Shakhtar draw, insists Nagelsmann|
|Valencia 0 Juventus 2: Pjanic hits the spot after Ronaldo sees red|
|Viktoria Plzen 2 CSKA Moscow 2: Krmencik heroics undone by late show|
|Benfica 0 Bayern Munich 2: Sanches returns to haunt his former club|
|Young Boys 0 Manchester United 3: Pogba double inspires Red Devils|
|Manchester City 1 Lyon 2: Cornet and Fekir stun Champions League favourites at home|
|Real Madrid 3 Roma 0: Isco stunner sets up winning start for Champions League holders|
|Ronaldo sent off on Champions League debut for Juve and may miss United reunion|
|Shakhtar Donetsk 2 Hoffenheim 2: Maycon denies Nagelsmann´s side|
|Ajax 3 AEK Athens 0: Tagliafico at the double in opening win|
|Dalot makes debut, Martial starts for Manchester United|
|India avenge ICC Champions Trophy loss with big win over Pakistan|
|Ronaldo makes Champions League debut for Juve|
|Lopetegui picks Navas over Courtois for Champions League clash with Roma|
|Willian very happy under Sarri after Conte row|
|Sarri deals blow to Chelsea kids´ Europa League hopes|
|Mendy out for Manchester City as Aguero makes bench|
|Cech accepts performances key to securing Arsenal stay|
|Monchi rules out Spain return amid Barcelona rumours|
|Durham skittled for 61 and 66 on the same day|
|Kane isn´t a machine – Lamela defends misfiring Spurs star|
|Hazard left out of Chelsea squad for PAOK trip|
|Tiger feels close to ending drought after achieving Tour Championship goal|