When news filtered through of Robbie Henshaw's troublesome hamstring, it must have reinforced Joe Schmidt's message to those left behind about being ready, if called upon.
Immediately, the request was made for Will Addison to be pulled out of Ulster's pre-season hit out against Glasgow Warriors.
He would have had a nerve-wrecking wait to hear the results of Henshaw's scan yesterday.
The fact Addison was joined by Jordi Murphy and Kieran Marmion in staying on for the final week in Carton House after being cut by Schmidt indicates just how close they came to having a dream come true.
These are the five men most likely to make it to Japan before the end of Ireland's World Cup adventure.
The versatile back comes with a fine playing pedigree and the added layer of leadership that comes from the captaincy of his former club Sale Sharks.
It is reasonable to suggest the 27-year-old would have made it to Japan were it not for his late start to pre-season.
He was restricted to just one appearance, at full-back, in the third warm-up match, impressing with his composure and game awareness.
There were eyebrows raised when the Dubliner was left out of Schmidt's official party of 31.
A long-time favourite of the Ireland coach, Murphy could be forgiven for harbouring resentment towards the man who would have supported a move to Ulster.
Moreover, the all-purpose back rower has spoken at length about how the switch was premeditated on international ambition and the desire to make it to the World Cup.
The unlucky scrum-half did not feature for Connacht in their win against Russia in Moscow last week.
Schmidt's decision to go with Luke McGrath over Marmion came down to just one aspect of the game - kicking.
It is safe to presume the 27 year-old has been concentrating on that element, above all others, at The Sportsground, in case of a call from the Far East.
It was interesting to note how Devin Toner was nowhere to be seen for Leinster in Northampton on Thursday night.
The prospect of a match to take out his frustrations on Saints for missing out on the World Cup would have been a benefit.
Perhaps, the Meath man has been given a short spell to recalibrate in light of his three appearances for Ireland last month.
Hooker Herring started in Ulster's 36-33 defeat to Glasgow Warriors on Saturday afternoon.
This probably had something to do with the fact he earned just one cap in August as a back spasm interrupted his World Cup plans.
Should something go awry with any of Rory Best, Sean Cronin or Niall Scannell, especially at the early stages of the tournament, the 29-year-old will surely be summoned by Schmidt.