Comment: Ireland's decision not to bring in Will Addison yet is a risky gamble as injuries mount ahead of World Cup opener
Squad management is a tricky business at World Cups, as Joe Schmidt well knows from the experience four years ago.
Rugby round up Newsletter
Back then, he lost five key players in a 10-day period around the final pool game and the team never recovered for their quarter-final against a rampant Argentina.
Now, he has lost two of his starting backs for the crucial opening fixture against Scotland and, with major doubts surrounding Keith Earls' fitness, he has little margin for error five days out from the crunch fixture of Pool A.
Moyross native Earls endured a disrupted pre-season and was selected to face Wales in the final warm-up game. He didn't finish that fixture and, although he turned away the stretcher and limped off, he remains something of a 50-50 call for Sunday's game.
Carrying him to Japan was a no-brainer, but losing Robbie Henshaw to a hamstring injury on the first day of training was a significant blow.
Yesterday, scrum coach Greg Feek gave what he described as a "reasonably positive" update on the Athlone native's muscle problem.
No detail was forthcoming, and he's definitely out of the opener, but the former All Black says Henshaw is still in the mix for the second fixture against Japan.
Please log in or register with belfasttelegraph.co.uk for free access to this article.
That looks optimistic. The IRFU were never going to confirm if it was a Grade 1, 2 or 3, but even the least serious option on that scale puts you out for three weeks.
He may have access to the best medical care, but Henshaw knows better than to push something as delicate as a hamstring.
Still, keeping him seemed like a clever play. It was a gamble, but the percentages were in Schmidt's favour and, even if Earls missed the game, the coach had adequate cover in the two affected positions.
Then, Rob Kearney injured his calf and the squad grew that little bit thinner. An update on the experienced Louthman's injury was to be delivered last night, but the initial word is not good and Scotland looks increasingly unlikely.
So, Schmidt is faced with potentially selecting all of his outside backs for Sunday's opening game.
Even the good news on Joey Carbery, who returned to full training yesterday, is tempered by his lack of serious game time.
If we presume Johnny Sexton and Conor Murray start at half-back, with Luke McGrath and Carbery or Jack Carty covering, then there are six slots to be filled by six available players.
It is key to bear in mind the forecast for thunderstorms and rain in Yokohama when considering the options.
Jordan Larmour would be expected to start at full-back, with Andrew Conway the stand-in for Earls if he doesn't make it and Jacob Stockdale on the other wing.
If Earls is fit, then Conway is an option at full-back and so is Carbery, who has never started in the No.15 jersey but has covered the position off the bench a number of times. Conway slotted in there for the final quarter of the win over Wales in Cardiff last month.
In the centre, Bundee Aki will be partnered by Chris Farrell or Garry Ringrose. Whoever doesn't get picked will be in the No.23 shirt.
Ringrose has been deputising there in the warm-ups, but would be considered the next man in line for the No.13 jersey.
However, Farrell's power will come into play, with Schmidt likely to favour a conservative approach given the inclement weather. It's still a good backline, but the coach will be acutely aware of the risk of injury.
If he loses one of his six fit backs, he risks needing to call Will Addison up cold and pressing him straight into service against Japan on Saturday week having just made a mammoth journey to get to Asia.
Although tournament rules forbid Ireland from bringing a back-up player over to train with the team or stay at their base, there is nothing to prevent them having Addison somewhere in the country, ready to go in case of emergency as long as they are picking up his travel and hotel bill.
At the time of writing, however, the former Sale Shark is back in Belfast and continuing his pre-season.
While his focus will be on getting the fit players onto the pitch and performing in a crucial opening fixture, the coach will also be asking questions of his strength and conditioning and medical teams after two players went down with soft tissue injuries within days of arriving.
Given the amount of data available, that seems a curious one.
Still, they will press on with their plans to train today and then move across Tokyo to Yokohama tomorrow ahead of their big kick-off.
They'll be saying prayers that no more backs get injured, but they will also be considering their decision to keep the injured players here to recuperate in the hope they'll be able to play a role further down the track.
Increasingly, that looks like a risky gamble, but for now Schmidt is willing to stick with what he has rather than twist and call for back-up.
His squad is set to be tested, so he'll be hoping it's as strong as it looked when it was named.