Dublin - Ireland flanker Sean O'Brien's injury jinx struck again when he suffered a broken arm at the end of the first half of Saturday's Test against Argentina.
The 31-year-old - one of the stand-out players of the British & Irish Lions' 1-1 Test series draw with world champions New Zealand last year - went off with his face creased in agony and then sat on the sidelines for the second period in what was his first Test in almost a year.
"Sean's broken his right arm," Ireland head coach Joe Schmidt told RTE.
"He'll need surgery on that."
Schmidt said later in his post-match press conference everyone was devastated for the player known as 'The Tullow Tank'.
"He is gutted, I am gutted for him and so are the other players," he said.
"He was just getting into his rhythm. I was talking to him after the game and he is already thinking of rehab and his big goal in a year's time (the World Cup).
"I think I described him as stubborn on Thursday and that resilience and stubbornness gives him a chance of getting back and into the Six Nations (which begins next February)."
O'Brien, who Schmidt said brought "contagious enthusiasm" to the squad and praised his resilience in continually coming back, missed both the Six Nations Grand Slam campaign and the 2-1 Test series victory over Australia due to hip and shoulder injuries.
O'Brien is definitely out of the clash with New Zealand next Saturday but Schmidt is blessed with talent in the back row.
However, he is hopeful centre Robbie Henshaw will be fit despite pulling up in the warm-up with a hamstring injury.
"Robbie, I'd be hopeful he will be ok but we have to just wait and see."