If the rationale behind the explanation for last weekend's line-up against Samoa still applies, Ulster centre Luke Marshall will be in Ireland's midfield for Saturday evening's Aviva Stadium date with Australia (5.45pm).
A week ago, when he unveiled the side for his first match in charge, new Ireland coach Joe Schmidt was asked about his decision to opt for Leinster's Gordon D'Arcy rather than Marshall.
His reply was: "Luke was really close and it's been great to work with him in the last two weeks. I've learned a little bit more about his appreciation of the game and he's definitely a raw talent and he's developing well.
"I still think there's some experience that needs to be added to that and you get that experience by continuing to play at Heineken Cup level and then getting opportunities at Test level.
"Unfortunately last year he didn't get as many opportunities as he would have liked.
"He has impressed us so far this season, but probably, for Luke, it was a disadvantage a little bit that Paddy (Jackson) is there – not that that's any disrespect to Paddy at all; it just meant that we could put that bit of experience with Conor (Murray) and Gordon (D'Arcy) either side of Paddy just to make that as comfortable as possible rather than have two young guys there together."
Paraphrased, to have included 21-year-old Jackson and 22-year-old Marshall side-by-side at outside-half and inside-centre would have been an unnecessary risk.
Yes, they are provincial colleagues in those same positions, but Test match rugby is a step up from that level.
With Jonathan Sexton ruled out last week by a hip flexor injury, Jackson got the nod to start at 10 ahead of 24-year-old Leinster player Ian Madigan.
So with Schmidt – not unreasonably – having decided that having two young, still-inexperienced international footballers in tandem was a situation best, and easily, avoided it was the unfortunate Marshall who found himself picking up the tab
This time, though, it is different. Sexton is fit to resume, so he will be named today as Ireland's number 10 to face the Wallabies.
And just as Jackson was 'nursed' last time out as a result of having seasoned internationals Murray and D'Arcy either side of him, on this occasion it is Marshall who will be the beneficiary of the presence of Sexton and Brian O'Driscoll on his left and right sides.
With Australia fourth in the IRB world rankings, Schmidt will bring out his fit-again big guns for Saturday's battle, with three of those who joined the fray from the bench against Samoa – captain and lock Paul O'Connell, loose-head Cian Healy and open-side Sean O'Brien – all starting on this occasion.
Had he been fit, Ulster's Chris Henry would have been O'Brien's understudy. Alas, a hamstring tear means he will play no further part in the three-match series which ends with an Aviva Stadium showdown against New Zealand, the world champions, on November 24. Henry's unavailability finds Leinster pair Kevin McLaughlin and Shane Jennings plus Munster's James Coughlan in contention for the number 20 shirt.
The fact that Lions wing Tommy Bowe was able to train on Tuesday after suffering a bruised calf against the Samoans has given cause for optimism that the Ulster ace will be ready to face the Wallabies.