Australia is looking to secure a place in the round of 16, where they could face the winner of Argentina and Cape Verde. But first, they have to overcome a major hurdle: Egypt, led by Salah.
However, the African star's participation is in doubt due to injury, and his possible absence would certainly be an advantage for the Australians.
"We are prepared for both scenarios," said the Australian coach Popovic. "We have analysed both the matches where Salah played and those where he was absent, observing the players who took his place. We are ready for either situation and tomorrow we'll see what the decision will be."
Australia comes into their first knockout match of this World Cup after earning four points from a win, a draw, and a loss in Group D. But for Popovic, his team has shown steady growth throughout the tournament:
"We are feeling very good. We know we earned this achievement and have shown our value in the group stage. We feel relaxed, confident, and prepared," he enthused.
"Tomorrow, we want to deliver our best performance. We have great respect for our opponent: like us, they also want to claim their first win in the knockout stage.
"It will be a special match and we are happy to have made it this far. We want to represent Australian football on the world stage once again."
He continues: "I've seen significant growth in the boys. In the second half of the last match, we were really proud of them.
"The way they responded shows maturity and a growth that is happening very quickly. Against Paraguay, we showed maturity, confidence, composure, and resilience, all qualities that are essential at this level. I'm convinced that tomorrow the boys will be ready to take another step forward."
Finally, a comment on the round of 32 matches played so far: "Knockout matches always have a different level. We've seen games decided by penalties, which are very exciting for the fans, and others, like today's match by Spain, dominated and won with authority.
"We have always believed we have the level to be here, and tomorrow we'll have another chance to prove we deserve this stage."