In recent years, Sean O'Brien has fought back from multiple shoulder, hip and hamstring injuries. He picked up a fresh blow on Saturday night
Sean O'Brien cut a distraught figure as he left the field of play after 38 minutes. The Leinster back-row had been performing solidly before breaking his right arm in what initially looked to be a regulation carry in his side's 28-17 victory at the Aviva Stadium.
O'Brien damaged his arm near the end of a hard-fought first half. The ball popped up to him with Argentinean players bearing down on him but, typically for the flanker, he ventured on.
Extending his arm to fend off the oncoming Argentines, O'Brien collided with the ducked head of one. Play would continue on around him but it was he was in serious discomfort.
The medics rushed on at the next break in play but it was clear that O'Brien would not be playing on. Dan Leavy was readied and came on in the final minutes of the half.
Johnny Sexton knocked over a penalty from near the halfway line and that distracted many of the home crowd from the unfortunate sight of O'Brien leaving with his jersey being used as a make-shift sling.
Following the game, Ireland head coach Brian O'Driscoll confirmed the bad news to RTE: "Sean has broke his right arm. He'll need surgery on that."
That means O'Brien is out of the remainder of the Guinness Series - matches against New Zealand and the United States - and he looks likely to miss Leinster's end of year Champions Cup and Guinness PRO14 commitments.
The positive for Ireland, however, will be the solid performance registered by Leavy in the second half. The flanker gave away an early penalty but was flawless thereafter as Ireland pulled away from Los Pumas to record their 10th consecutive win, a record for the national team.
