Big-name absentees will barely register with Schmidt's focused men
As a player, if you're in the right environment, you don't spend any time thinking about team-mates who won't be playing.
I was trying to think of times when big players were ruled out of big games I was playing in, and I could barely remember any. And not because there weren't any. It's just that we didn't make a big deal of it.
Brian O'Driscoll missed a key Heineken Cup pool game for Leinster in Clermont in December 2010. But that only stood out because he came with us and did water-boy duties, and because Eoin O'Malley stepped in and played a stormer.
I don't remember anything being different in the build-up. Drico's absence barely registered with us.
Maybe the professional mindset is just different. In the week before a game, you hear so much from the public and the media about the guy that's not going to be there. But as a squad, you really don't focus on what you've lost. The last time I worried about absent players was in schools rugby.
That will be Ireland's attitude this week.
One of Joe Schmidt's strengths is keeping all the uncontrollables out of camp.
And Joe has built a squad, not just a team. The guys coming in have played in big games - Joe will have planned for every eventuality.
I have no doubt that Jordi Murphy, Rhys Ruddock, Chris Henry and Iain Henderson will step in and do as good a job as the people they are replacing.
It's not like Joe is plucking a guy out of the PRO12. He has created serious depth - a squad where anyone can step in and perform the role.
Of course, Paul O'Connell is a big loss. He's an inspirational leader. I could tell from playing against him. I remember being down by two points at Thomond with three minutes to go. I tried to regather our restart, missed it and got trapped under a load of bodies at a ruck.
Paulie took full control. I could hear his voice, 'Look at the clock, four pick-and-goes till the game is over'. Hearing his calm authority, I just knew we weren't getting that ball back and they were going to win.
I would have loved to be involved in a team with him, just to see him operate.
You can't replace O'Connell directly, but you've got other leaders in key areas - Rob Kearney, Rory Best, Jamie Heaslip and Conor Murray. There's enough voices to fill the void.
Just look how well Ireland played after he and Jonathan Sexton went off last week.
Peter O'Mahony is also a loss - he's one of those guys that always gives a little bit more. And obviously Sean O'Brien.
And while Joe will make sure Ireland are not thinking about who isn't playing, their absence will give Argentina the fuel to be even more physical.
I've seen a lot of the Pumas, and they are twice the team they were three years ago, because they've been involved in the Rugby Championship.
They're playing three top nations twice a year. Graham Henry went in and did some consultancy - a great mind in the mix, and that helped.
They're physical, the set-piece is strong and they're also sharp - they've got some of the most exciting backs in the game.
The good news is, there's no danger of Ireland being complacent. Joe doesn't do complacency.
The public might think they have an 'easier' quarter-final, but players don't think like that, certainly under Joe. I remember Leinster played Cardiff in a Heineken quarter-final in 2012, and they would have been considered the easiest opposition, but that's the worst mindset to get into.
You stop it by thinking of the process, of executing a role and keeping your same standards, as you would have against a stronger team.
If you're in that mindset, it doesn't matter what team you come against or who is missing from your line-up, you deliver.