Sevu Reece and George Bridge add a "fearless" edge to New Zealand's squad for the Rugby World Cup quarter-final tie with Ireland, according to assistant coach Ian Foster.
Reece and Bridge have both impressed so far for the two-time defending champions in Japan and have made the cut for Steve Hansen's XV against Ireland on Saturday as two of the world's best teams face off.
The duo's inclusion sees Rieko Ioane and the experienced Ben Smith miss out on Hansen's 23-man squad, but Foster believes the World Cup debutants can be key.
"There is a little bit of fearlessness about them," Foster told a news conference.
"Some of it is probably because they haven't been at a World Cup before, they probably don't what is at stake, in some sense.
"But they are really sensible young men. They train hard, they play hard. When you haven't got Ben and Rieko in the group, that is a tough decision, because they are two pretty special people in our group.
"We just felt that George and Sevu have done enough. There is a bit of spark there and we will run with that."
Ireland lost to hosts Japan in their second outing but comfortable victories over Scotland, Russia and Samoa saw them progress, as they recovered some form following doubts coming into the tournament.
Foster sees confidence and momentum as the deciding factors in this last-eight tie.
"I am pretty sure they will have some tricks up their sleeve, and we like to think we have got a couple up our sleeve," he added.
"That is the nature of preparing for a big Test match. But to be honest, games like this are often not about a special trick or surprise. It is about your confidence, how you deal with the pressure and how you keep executing your own game.
"It is one thing to know each other's game, it's another to execute it properly and to stop the other person doing it. That is what play-offs are about, it is about having that composure to trust yourself and really back yourself to keep doing what you do well."