No sooner had Ireland come to terms with the end of captain O’Connell’s World Cup and Test career due to a torn hamstring than head coach Joe Schmidt was hit with another blow.

Schmidt will now be forced into a major pack reshuffle against the Pumas, with Iain Henderson and Chris Henry expected to start in Cardiff on Sunday.

O’Brien hit Pape in the solar plexus in the first minute of Ireland’s 24-9 victory over France on Sunday, with Les Bleus boss Philippe Saint-Andre later branding the incident an “assault”.

A World Rugby statement read: “O’Brien admitted committing an act of foul play and therefore the independent judicial officer Terry Willis upheld the citing.

“With respect to the sanction, the Judicial Officer deemed the act of foul play merited a low-end entry point of two weeks. The judicial officer took into account compelling mitigating factors including O’Brien’s conduct prior to and at the hearing, his remorse, good character and clean disciplinary record, and reduced the suspension to a period of one week.”

That means that O’Brien would be available for a potential semi-final against Australia or Scotland.

O'Brien's ban brought to a close a day of high emotion and no little legal wrangling for Ireland, that started with a string of tributes to long-serving skipper O'Connell.

Ireland confirmed on Tuesday morning that O’Connell needs surgery on his torn hamstring, leaving the 35-year-old unable to add to his 108 caps.

O’Mahony flew home to Cork on Monday after suffering serious knee ligament damage against France, leaving Ireland requiring several shifts in their pack.

Rhys Ruddock arrived to replace O’Mahony while Mike McCarthy was drafted in to offset O’Connell’s absence.

Ulster flanker Henry has insisted Ireland can cope without twin enforcers O’Connell and O’Mahony against Argentina in Sunday’s last-eight clash.

Ireland bosses were still holding out hope that linchpin fly-half Johnny Sexton could beat his groin trouble in time to feature against Argentina, keen not to see their ranks any further depleted.

Henry revealed he shed a tear at O’Connell’s tub-thumping rhetoric ahead of Sunday’s superlative victory over France – now the back-rower believes few words will be required for Ireland to psych themselves up for Sunday.

“The team talk does write itself ultimately this week,” said Henry.

“There’s a lot at stake and Jamie (Heaslip) speaks really well, but I don’t think it’s going to need too much speaking.

“Everyone’s very, very focused, you can see it in the way people are floating around the place at the moment.

“Having that extra 24 hours was a big pushing factor and I think we’re going to need that rest.

“Not too many words will be needed.

“The bus journey into the Millennium Stadium last week before France was crazy.

“The noise when we were warming up, the roar when big tackles or breaks were made, the atmosphere was phenomenal and we’ve no doubts it will be there and thereabouts again this week.

“Paul and Pete set the tone for what followed on the pitch last week and hopefully that’s some small solace for them.

“They were playing unbelievably and that’s the heartbreaking thing.

“And if we can use that as any extra motivation, if it can give us just one per cent more in terms of performance, then we’ll try.

“And we want to do it for those players, they’ve given so much not just in the last five weeks, but in the last decade.

“So it would be incredible to do something special for Paul and Pete.

“Sunday will be about how we front up on the pitch – if you look at past games whenever Ireland have faltered it’s usually Paulie that generates something, smashes someone or gets the ball and does something different.

“He just keeps going when there’s a brick wall in front of him.

“If we can use that as inspiration then we will.”