JEDDAH, Saudi Arabia -- It grows as you approach the King Abdullah Sport City Stadium, first as you snake your way through the lines of traffic that clog the roads to the ground, vendors darting between cars with merchandise in hand, and becoming more and more ferocious as you near the pitch. Sheer, inescapable and overpowering noise. It increases as kickoff approaches and reaches a 90-minute crescendo when play begins, a cacophonous barrage of cheers and unforgiving jeers and whistles that alternates depending on whether the home side has the ball.
This is the crucible that awaits the Socceroos when they conclude the third phase of Asian qualification away to Saudi Arabia next month. Currently occupying the second of two automatic qualification slots in their group, Australia will host already-qualified Japan in Perth on June 5, knowing that a win -- thanks to their healthy goal difference -- effectively punches their tickets to the 2026 FIFA World Cup. Anything less, however, means that the Socceroos face the prospect of needing to avoid defeat in Jeddah to ensure they won't be overhauled by the Green Falcons or, should Indonesia defeat China before stunning Japan, needing a win to avoid being leapfrogged by Patrick Kluivert's Tim Garuda.
Defeating Japan, thus, would spare everyone a lot of nerves heading into the cauldron of the King Abdullah. But in Asia, that's very much easier said than done: the Samurai Blue unbeaten since their disappointing Asian Cup exit last year and outscoring their opponents 35 to two. Perhaps at the end of a long European season and with qualification already assured, Hajime Moriyasu will rest his established stars in favour of exposing less experienced players to international football? But even then, one only needs to examine the recent run of Kawasaki Frontale in the Asian Champions League Elite to see what unheralded J1 League players can do.
"I'm sure they'll come with a mindset of winning," Socceroos coach Tony Popovic said. "They haven't lost a game in the campaign. They've been the best team, there's no doubt about that.
"If they do change any players, if some of the J1 League players come in, I'm sure they want to prove their worth to the coach, because they also want to go to a World Cup."
Should it come down to Jeddah, Popovic can at least fall back on previous experiences of travelling to the Gulf and returning with a result. In 2014, holding onto a slender 1-0 lead from the first leg in Parramatta, he led Western Sydney into Riyadh's King Fahd International Stadium and ground out a 0-0 draw with powerhouses Al Hilal, securing Australian club football's greatest ever accomplishment.
After a whirlwind start to life as Socceroos boss, his demeanour in the squad's last camp in China spoke to a more assured figure, too. The squad's foundation increasingly fits his vision, one he trusts to meet his expectations both on and off the field. There was an air that those still in camp -- there has been plenty of behind-the-scenes changes since Graham Arnold's exit -- have settled into their roles and that while standards are as high as ever, there's constant reflection of what's worth stressing during the limited time the coaching staff has with the team and what isn't.
"We want to keep improving. Want to keep getting better. We want to be able to keep giving and delivering the players something new, something different that we're adding to our game," assistant Hayden Foxe told ESPN in Hangzhou.
"You're always tweaking. We're always looking back through the train sessions ... and we're constantly challenging each other. You have to challenge each other. That's how you keep getting better.
"That's not being negative, that's not being fearful, that's asking how we can get better? How can we keep growing as a staff?"
All this, however, is complicated by the loss of Jackson Irvine to a foot injury. Up to this point, the St. Pauli captain was the first name on the Socceroos teamsheet, with Popovic remarking last window that if he could trust any outfielder to get straight off a plane and play two games in quick succession, it was the Victorian. And this reliability has been reflected on the pitch, as he logged 90 minutes in all bar one of the Socceroos' games under their new coach and increasingly showed his utility as a box-crashing weapon. Reflective of his steadying presence and leadership, his withdrawal in the Socceroos' qualifier against Bahrain was soon followed by two Bahrani goals, forcing the Socceroos to salvage a 2-2 draw through a 96th-minute Kusini Yengi equaliser.
"It's certainly a blow," Popovic said. "He played very well for us in the last window and he's doing very well with St Pauli. But we have to find a solution."
But given the stakes of the June window, just how Popovic attempts to find a solution for Irvine's absence could prove one of the most pivotal decisions of his tenure.
"We're trying to see what profile we need in midfield," said the coach. "Do we want someone more similar to Jackson, with the way he gets forward really well and can get into the box late? Or do we want someone who can control the game in our buildup? We've got to balance all that out and see what the options are.
"We could set up with two midfielders in there that are maybe similar, but we may need to look at a different profile for a different position to get more out of another player, getting forward and getting into the box of crosses and cut-backs."
The most predictable replacement for Irvine, especially when accounting for the premium Popovic places on reliable professionals who have multiple seasons in their legs, is Aiden O'Neill -- who recently completed a move from Standard Liege to MLS side New York City FC -- and is a relatively plug-and-play fit next to Ryan Teague.
But after showing a willingness to return, Massimo Luongo could come into the frame despite limited minutes in the Premier League for Ipswich Town. So too, could Riley McGree if he's fit, or Ajdin Hrustic should his re-emergence at Salernitana continue. In light of their continued minutes in Scotland and the Netherlands Nectarios Triantis and Maximilien Balard, respectively, should also come into contention, as could the likes of Patrick Yazbek, Anthony Caceres, or a Luke Brattan-esque bolter that few expect.
This, in turn, flows into other areas. Does your approach now need a facilitator like Adam Taggart up top or a mad presser like Mitch Duke? Does it call for the fleet footwork of a Daniel Arzani or the purposeful presence of a Nestory Irankunda?
All players bring unique strengths and weaknesses. All have preferred areas of the pitch they like to occupy, both in and out of possession. All approach receiving the ball and what they look to do with it differently. And this all affects the collective in different ways. Thus, the challenge for Popovic isn't replacing Irvine as it is finding the right combination of players within his overarching framework to replicate, if not better, the output with him.
"We've just got to balance it out," he said. "You're looking at the opponent, trying to see where the best opportunities lie for us against Japan. In what areas of the park? Is it wider? Is it more centrally off crosses? We'll have to consider all of that before we pick a squad of players that can make a difference in both games."
Joey Lynch is in Jeddah reporting on the AFC Champions League Elite Finals as a guest of the Asian Football Confederation.