For some, they will have to think about what might happen if they come out of the All Blacks for five or six tests. They might find that it's not as easy to get back in.
Other guys might be tempted by the sevens opportunity but will also be thinking that they may have a chance to establish themselves in the All Blacks.
I think we saw that with Aaron Cruden — that with Dan Carter not around next year, he'll have an opportunity at No10 so has turned down the sevens opportunity.
The other thing guys will have to consider is that even if they do commit to sevens, there is no guarantee they will make the Olympic squad. They are going to have to ask themselves whether they believe they are good enough to compete for places against those guys who play on the circuit all the time.
And that's the thing that I would stress having played a bit of sevens — the basic skills of pass and catch are the same but the fitness requirements are totally different. That's the hardest part — being able to get used to the demands of sevens which are different.
You never stop running in sevens and it doesn't matter how tired you are. I remember when I first played, Eric Rush saying that to me — that no matter how much fatigue you are feeling, you have to keep moving.
You might make a 60m, or an 80m sprint for a try and then come back into position and have to go again. You also have to play three or four games in a day and then back it up the next day.
That's different to fifteens when you can pretty much always manage to find a way to have a bit of a rest and get your breath back.
So there is no doubt the athletes that have been targeted — the likes of Sonny Bill Williams, Julian Savea, Beauden Barrett and Ben Smith — are all great players and are all fit, but that doesn't mean they can play sevens or that an Olympic gold medal will come easily.