What if? What if? What if?
The words of Matildas head coach Tony Gustavsson echoed around the silent conference room at Stadium Australia following Australia's tense 1-0 win over the Republic of Ireland on Thursday night.
Like the ticking of the tell-tale heart beneath the proverbial floorboards, the repetition paralleled the throbbing anxiety that swept around the stadium when, just an hour before kick-off, it was revealed that captain Sam Kerr had withdrawn late due to an injury she'd sustained two days earlier.
Suddenly, the media conference that she and Gustavsson had given the day before the match had a bizarre feeling of unreality to it.
Sitting there on the Wednesday night, both of them knew exactly what had happened: They were there in Brisbane when, during a gentle warm-up before their final training session, Kerr peeled off from the main group after feeling a pull in her calf.
Yet when previewing the match to a packed media room, they pretended otherwise. They joked and jibed with each other, speaking in the present and future tense about what they were expecting, rolling out the carpet of a future that they knew they would not walk down.
It was, in hindsight, a surreal moment. Kerr occupied this strange in-between space on that stage, both there and not there at the same time. This was the same space she occupied for the entire next day, in the headlines and the newsreels and the conversations of thousands of fans making the pilgrimage to Olympic Park to see her.
She was still present in all of our realities — still very real in all of our minds — until she wasn't.
After the match, in which Australia clearly struggled without her, Gustavsson was asked whether he had planned for "the worst-case scenario".
"You always want to be on track and focus on the positives but, as a coach, your job is also to look at different scenarios," he said.
"What if a centre back goes down? Or what if an outside back goes down? Or what if we play without Sam [Kerr]?
"We've had a couple of opportunities to play without her in this two-year preparation. I think it was important for the team to feel those 30 minutes against France in the send-off game, when it was 0-0 and both Sam and Caitlin [Foord] stepped off. We managed to win 1-0.
"But you don't go there too often with those thoughts as a coach because you just get nervous if you do that."
Nobody ever expects the worst-case scenario to happen, of course. All those rehearsals — against France, say, or last year's disastrous window against Spain and Portugal, where Kerr was one of several senior players deliberately rested — are always based on hypotheticals. On the imaginary what-ifs.
There is a kind of comfort created in these imaginary friendly spaces. As a coach, you can play around with tactics and formations, try out different characters in different roles, and act out different scenes, like a child digging through a dress-up box.
Yet those games are always played safe in the knowledge that the sword and cape will eventually be returned. That this was all just pretend. That you won't actually have to live out your worst-case scenario.
But on Thursday night, that is exactly what happened. The imaginary became real: Sam Kerr, the Matildas' star player and face of her home World Cup, was injured.
She'd be out not just for this record-breaking opener against Ireland, but also potentially for the next game against Nigeria as well. Two games in which Australia had to secure results before the final group-defining game against Canada.
How do you adjust, on the cusp of a moment like this, to the loss of a player with a gravity as supermassive as Kerr's?
They tried their best to on the field. Foord, Mary Fowler, Cortnee Vine and Hayley Raso all took it in turns switching in and out of Kerr's centre forward position, trying on the hat and the shoes, only to find they never quite fit.
The team looked disjointed as a result. The long-range and line-breaking passes that Katrina Gorry and Kyra Cooney-Cross have sharpened while playing with Kerr over the past year — knowing exactly the speed and angle at which she wants to receive the ball — trickled away into the vague, empty spaces where the imaginary Kerr might have been.
This is the paradox of having a player like Sam Kerr on your team. Her galactic talent is what gives the Matildas their world-conquering potential, it is the thing that can take them all the way. But it's also the thing that is impossible to replace when she goes missing.
On the field, it's almost like her reputation is a physical object; something that has its own mass and magnetism. It's not necessarily her goalscoring but her threat of goalscoring that is her most powerful asset. The fear she creates in opponents can pull the fabric of a game apart.
Even if she's not the one scoring goals, she's the one dragging defenders out of shape so that her teammates can. Kerr is one of the few players at this World Cup who has such a presence, who can command the physical and the metaphysical space of a game at the same time.
Gustavsson has tried to find answers to the Kerr Conundrum.
In the send-off game against France, the game-winning goal was scored without Kerr's presence on the pitch at all.
And yet, such is her power that the sight of her walking off the grass arguably created a sense of complacency — even relief — in the French defenders who were then startled by the goal that was scored minutes later.
She is still present, even when she is absent.
The same went for Thursday's win over Ireland. Although she sat on the sidelines, her absent presence was still felt by her teammates, who were out there working twice as hard to fill the void she'd left behind.
"To have her go down a day before a moment like this was pretty awful," vice-captain Steph Catley said afterwards.
"But I think, as a team, it added something to us. It added a fire, it added a little bit of extra fight. I think everyone looked at it and said, 'I've got to step up now because we don't have Sam.'
"And Sam's still around. She's in every meeting, she's in there at half-time talking to everyone, she's doing the pre-game talk. She's Sam and she's still with us, so we'll do everything we can to get as far as we can, and then hopefully we see Sam later on."
"We know that she was with us the whole game," Ellie Carpenter said, "and we did this win for her.
"She's always supporting, she's always there, she's always in the change room before, during, after. We can always hear her."
Indeed, Gustavsson used Kerr's reputation to his own advantage the day before the match, too.
Of course, it's normal that coaches don't reveal their tactics to rivals before a game has been played. But this wasn't just tactics. Such is Kerr's importance to the way the Matildas play that even the slightest adjustment to her role could totally reshape the way Ireland prepared for Thursday.
"I hope you respect and understand the reason, when I sat here yesterday, that I couldn't speak openly about it," he said.
"Sam [was] a massive part of Ireland's game plan, as you understand. And we didn't want to give that away in advance.
"But once we came to the stadium, we didn't play any type of mind games. We were honest with the team sheet. She wasn't in the starting line-up. We went out with the news saying she couldn't play, but we wanted to wait until the last second to not give away too much in tournament football."
But now the secret is out.
Nigeria is just six days away, and the original plan they may have had to contain the world's best striker has now been torn to shreds.
They've got more time than Ireland had to prepare something new, to find ways to exploit the weaknesses that Kerr's presence can sometimes eclipse.
So now it's the rest of us who sit in our quiet rooms, clinging desperately to daily updates on the mystery status of a lower leg muscle, asking ourselves the same echoing question: What if? What if? What if?