Cronin faces unclear future after crucial mistake in first Test
This is a ruthless business, and nobody in Ireland's travelling party knows that better than Sean Cronin, who wakes up in Melbourne this morning unsure whether he has an international future.
The 32-year-old hooker has enjoyed a fine season for Leinster and fought his way back to the bench for the Six Nations games as Rory Best's back-up.
When the captain failed to recover from a hamstring issue in time to travel there was an expectation that Cronin would step up.
Instead, he has endured the frustration of being leap-frogged by Rob Herring into the starting XV for the first Test and the indignity of being left out altogether for the second as he takes the hit for a key 68th-minute scrum that went against his team.
It was a key moment in a close game and it appears to have featured heavily in the post-game reviews.
As well as the breakdown, the work under the high ball and the need to tighten up the basics on attack and decision making in defence, there is a pressing need for Ireland to ensure that they don't get turned over at scrum time again.
Summing up the approach of the front-row union, Cian Healy said yesterday: "The battle is everywhere, but for us our main one is in there.
"That's what we rank our game on. You could have all the carries in the world but if you don't back it up, that's s***. That's not good.
"So that's what we rank ourselves on and we have to take a bit of pride in it and put it forward and essentially give the backs the platforms or give the defensive structure the right platform as well to deal with anything."
There is no doubting Cronin's abilities in the open spaces, he possesses electric speed for a front-row player and is capable of leaving backs for dead, but the Ireland coaches harbour doubts about his work in the tight - out of touch and in the scrum.
That is a particular worry this weekend given the forecast for mixed conditions, which means poor handling will invariably lead to more scrums.
Size is an issue, and it may surprise fans to learn that at 101kg the Leinster man weighs in as the lightest of the three No.2s on tour.
In Brandon Paenga-Amosa (117kg) and Tolu Latu (117kg), Michael Cheika has plenty of heft between his props and that transfers into the kind of set-piece pressure that resulted in the pivotal scrum penalty.
Cronin is giving up two and a half stone to Paenga-Amosa, whereas Niall Scannell (110kg) is less than a stone lighter and is renowned for his abilities at the set-piece. Schmidt hasn't ruled out a return for Cronin but he now faces a real uphill battle to get back into the side.
"We always came with the intent to give a little bit of experience to guys and to give everyone a little bit of an opportunity," the coach said.
"One of the features from last week was the scrum, and we are hopeful Niall can add a bit of value in the scrum.
"We also felt that Robbie Herring got better and better as the game went on at scrum time and the other thing is our lineout was super last week and Rob Herring threw really, really well.
"So we know we are going to have to be really good at the set-piece.
"The forecast is mixed, so whatever it ends up being, it seems to vary much like Dublin does, it goes up and down, so there is a fair bit of thought and consideration given to all the selections and to that one obviously, and I would certainly defer to our experts in that area of the pitch to make some calls that will hopefully benefit the team.
"At the same time, we know how good Sean can be for us and has been over a number of years, so there is another opportunity next week, so we are probably trying to balance things through the three weeks."
Former Ireland winger Luke Fitzgerald was hugely critical of the decision, suggesting a personality clash was the real reason.
But that just doesn't tally with how the head coach does business.
He is far from perfect, but Schmidt is a thorough selector who ponders every facet of a player's potential contribution before settling on his decision; reviewing reams of game footage to ensure he is as informed as possible.
If he agreed with Fitzgerald's assessment that Cronin is the best hooker in Ireland, then he'd pick him on a week in, week out basis.
Instead, he has seen enough to have major doubts over the 32-year-old, who appears to have a difficult last week in Australia ahead as he tries to convince the coaches that they've called it wrong.
Otherwise, it might be a while before he's involved again - if at all.
How they line up
Ireland team: Kearney (Leinster), Conway (Munster), Ringrose (Leinster), Henshaw (Leinster), Earls (Munster), Sexton (Leinster), Murray (Munster); Healy (Leinster), Scannell (Munster), Furlong (Leinster), Ryan (Leinster), Toner (Leinster), O'Mahony (Munster), Leavy (Leinster), Stander (Munster).
Replacements: Herring (Ulster), McGrath (Leinster), Porter (Leinster), Beirne (Scarlets), Murphy (Leinster), Cooney (Ulster), Carbery (Leinster), Larmour (Leinster).