Schmidt vows to 'forge ahead' as O'Brien is ruled out for clash against Argentina
Joe Schmidt will "forge ahead" without Sean O'Brien for the quarter-final and Peter O'Mahony, Jared Payne and Paul O'Connell for the rest of the World Cup.
Openside O'Brien has been hit with a one-match ban for striking France lock Pascal Pape, making him unavailable to play against Argentina on Sunday.
This means Ireland will have to make two changes to their back row, with Chris Henry and Iain Henderson favoured to make the step up.
It couldn't have come at a worse time, given how O'Connell flew home yesterday to undergo surgery on his torn hamstring.
Schmidt has talked about how his captain will leave "a big hole" in the squad for his example to all others.
This all comes as out-half Jonathan Sexton battles against the clock to overcome a groin injury.