Ireland captain Dan Sheehan faces a spell on the sidelines after failing a head injury assessment during Friday night's 42-12 win over Argentina.
The Leinster hooker was having a pretty good evening in Dublin. He scored a try, Ireland were flying, and everything looked rosy.
Then came the bad news.
Sheehan was forced off after 35 minutes and failed his HIA. Rónan Kelleher came on, and the captain's night was over.
Now Ireland face an anxious wait ahead of next Saturday's Nations Championship clash with Fiji.
Andy Farrell provides Dan Sheehan injury update
Ireland boss Andy Farrell was quick to offer some good news after the final whistle.
"So we'll see tomorrow. Dan came off with a HIA, but seems fine, certainly in the dressingroom."
That's encouraging, but the medical team will have the final say.
Sheehan must undergo further checks before he can return. His place against Fiji on November 14 is far from certain.
It would be a bitter blow for the hooker, who had already crossed the whitewash in the 25th minute.
Ireland had recovered from an early Argentina try and were starting to turn the screw.
Unfortunately, Sheehan's injury wasn't the only talking point from a rather eventful first half.
Referee Luke Pearce also found himself in the firing line, with several decisions leaving Argentina supporters scratching their heads.
It certainly wasn't a quiet Friday night in Dublin.
Ireland face further injury concerns
Sheehan was not the only player to give Farrell a headache.
Ireland finished the match with several players requiring medical attention.
- Dan Sheehan: Failed his HIA and did not return.
- Robert Baloucoune: Forced off with an injury concern.
- Sean Jansen: Suffered a blow to his knee.
- Josh van der Flier: Picked up an ankle problem.
- Mack Hansen: Played on despite an ankle concern.
According to The Irish Times, Farrell confirmed that the medical team would assess the players following the match.
The timing is far from ideal, with Ireland preparing to face Fiji before a huge showdown with South Africa.
Ireland make winning start against Argentina
Injuries aside, it was a pretty good night at the office for Andy Farrell and his Ireland side.
Hugo Keenan stole the show with a superb hat-trick, while Sheehan, Sam Prendergast and Rónan Kelleher also got in on the act.
Keenan was the star of the show, earning plenty of praise in RUCK's Ireland player ratings against Argentina.
Six tries, 42 points and a winning start to the Nations Championship. Farrell could hardly complain about the result.
The injury list, however, is another matter.
With Fiji up next and the mighty Springboks waiting around the corner, Ireland will need all hands on deck.
And preferably out of the treatment room.
Rate the Ireland players vs Argentina
Who impressed you most during Ireland's 42-12 victory?
Was Hugo Keenan your standout performer, or did another player deserve the plaudits?
