Ireland's Sean O'Brien in trouble for punch

Sean O'Brien could be banned for this strike. Photo / Screengrab / ITV

Irish flanker Sean O'Brien looks set to miss the side's Rugby World Cup quarter-final against Argentina after video captured him punching Frenchman Pascal Pape in today's group D match in Cardiff.

Ireland won the clash 24-9 but could be without O'Brien and several other players who suffered injuries in the win.

Skipper Paul O'Connell was taken off on a stretcher with a hamstring tear, blindside flanker Peter O'Mahony was likewise with a knee or ankle problem, and first-five Jonny Sexton has an adductor injury.

Ireland coach Joe Schmidt said of a possible citing and ban: "It's not for me to determine. It's not a closed fist. I'd be hopeful... considering the dressing room at the moment with the amount of injuries we have, we can ill afford to lose another player, particularly a player of Sean's experience and standing in the group."

Stand-in skipper and No8 Jamie Heaslip said of the brutal match: "I don't know what it was like to look at... but it felt like a dogfight at times; a real slugfest between the two packs and then it was blown right open by both sets of backs playing some expansive rugby. The ball was going end to end at times."