Skipper Sergio Parisse and France lock Pascal Pape
are out but Australia's Will Genia returns at scrum half and the visitors still have the players to claim victory at Franklin's Gardens.
Les Bleus will also be without their talismanic leader Thierry Dusautoir, who has retired from Test rugby, as have fellow veterans Pascal Pape
and Frederic Michalak, leaving them pretty short of experienced figures, with no fewer than ten uncapped players in the 31-man squad.
However, when he looks back now, a part of him doesn't regret punching France lock Pascal Pape
- just the fact he got banned.
O'Brien has been banned for one match for punching France's Pascal Pape
, leaving scrum coach Greg Feek backing bullish back-five forward Henderson to help fill the leadership void.
Ireland are understood not to have any intention to appeal O'Brien's oneweek sanction, for punching Pascal Pape
in the 24-9 victory over France.
Leinster's bullish back-rower O'Brien has been cited for his off-theball skirmish with lock Pascal Pape
in Sunday's France clash, and will appear before a London disciplinary panel on Tuesday lunchtime.
SEAN O'Brien has been hit with a one-week ban for punching France's Pascal Pape
, leaving Ireland without three pivotal pack leaders for Sunday's World Cup quarter-final with Argentina.
Sexton is battling groin trouble, while O'Mahony has knee ligament damage - and O'Brien could face a citing for an alleged firstminute punch to France lock Pascal Pape
And Sean O'Brien could face a citing for an alleged punch on Pascal Pape
when the dust finally settles on this bruising battle in Cardiff.
Linchpin fly-half Sexton trudged out with a groin strain and nursing sore ribs from a hefty hit from Louis Picamoles, while Sean O'Brien could face a citing for an alleged punch on Pascal Pape
Ireland No.8 Jamie Heaslip suffered three fractured vertebrae in his back after being kneed by France lock Pascal Pape
, who was sin-binned for the offence and later cited.
The Falcons are not the only ones leaving big names out of their European squads, with group opponents Stade Francais omitting captain and Italian icon Sergio Parisse from their official list, along with France fly-half Jules Plisson and national-team lock Pascal Pape