Scrummaging will be tough. We all know the Pumas are a good scrummaging side and will target that area of the game.
If I was coaching them, I'd have the tighthead and hooker ever so slightly angle in on Harris. The trick in being able to do that is to change your body positions ever so slightly without making it obvious.
It's a hell of a place, hooker. There will be, let's say, half a tonne of weight pushing behind Harris and then the same again coming at him from the other side through the Pumas.
That's a lot of pressure and, if the tighthead and hooker are angled a fraction towards him, they will have the chance to pop him right out.
But I'm not suggesting Harris is vulnerable. Test football is all about being taken to your limits and having to find solutions to problems and Harris will have plenty of good players around him.
Within the All Blacks, there's a long history of players coming in and delivering almost immediately, even if there is uncertainty about whether they are ready.
Brodie Retallick pretty much came from nowhere and Aaron Smith wasn't part of the World Cup squad, probably wasn't even close, and look at him now.
Opportunity is sometimes all it takes for a career to kick-start. It's unlikely but if Harris can give a good account of himself in Argentina and Coles remains with his family, Harris could even start in South Africa.