There are two types of people in the world: morning people and the rest of us.
Jamie Heaslip is clearly among the latter. He can get through 26 full matches in a season against the world's best players and still be standing on the other side, but ask him to show up for an 8.00am press briefing and it's a different story.
Whichever side of the bed the Leinster captain emerged from, it was the wrong one. The charming, urbane restaurateur and tech guru was replaced by a cranky adolescent crying out for a cup of coffee.
Some caffeine and yesterday's down day should pick him up in time for one last game in the Ireland No 8 shirt before he can disappear for four weeks on holidays, where he intends to "get away from you guys" – the media.
Ireland's best-paid rugby player and renowned ultra-professional is often capable of a charm offensive when he reports for his press duties, but this wasn't a vintage display.
Perhaps it was the fact that he had been deprived of his weekly fix of 80 minutes of rugby that had unsettled him, while a packed tour schedule heavy on work and light on downtime hasn't suited a mind that needs to switch off.
"It's been intense, obviously we rolled out off the back of a pretty intense week and all the things that come with touring, travelling and staying in hotels," he grumbled.
"I was asked if I've seen anything and I've seen the hotel room, the training ground, hotel lobbies, which is a bit of a regret because we're in such a unique country but I'm lucky that I've been here before on rugby tours.
"It's been a bit of a rollercoaster coming on from previous weeks into this, where as soon as you arrive in camp it's intense."
So aware is Joe Schmidt of the limited windows available to him between now and next year's World Cup that the coach is packing in the work and making sure the players leave Argentina with an increased sense of what is needed to play for his Irish team.
Heaslip is a trusted lieutenant, his vice-captain and anchor at No 8. He will be restored to the starting XV after being left out for the first time under Schmidt's regime.
Indeed, it was the first Ireland Test Heaslip has missed since the 60-0 massacre at Hamilton two years ago, leaving aside the tour to North America last summer when he was being capped by the Lions.
Understandably, it was something of a surreal experience for the 30-year-old, whose only other appearance off the bench for Ireland came when he scored a crucial try at Murrayfield during the 2009 Grand Slam season. The last time he was a sub for Leinster was against Treviso in 2011.
"It was the second time I've come off the bench for Ireland. It was very different," he said.
"I found it tougher to prepare coming off the bench, because I've done it for Leinster and found it different but not hard, but on Saturday it was harder."
In contrast to Paul O'Connell, Heaslip isn't exactly pining for New Zealand and a Test against the All Blacks; his annual visits between 2010 and 2012 have put him off the pace.
"We made eight changes from the last Test game, so it's great in terms of building a squad going forward," he said. "If you want a strong squad you want guys who are confident and experienced.
"We've played New Zealand enough, I'm actually glad we're not there touring. Three times in three years was enough. It's nice to be on another continent."
And, that was that; back to bed, one hoped, for the sake of his team-mates.