For Barrett, a 23-year-old playing in his 28th test, it is the ideal chance to prove he is more than a utility player, an impact specialist. From running against the starting backline over the past couple of weeks, simulating the attacks of England and Scotland, he has control and is determined to make the most of his opportunity.
Asked whether he was aware of the debate at home around who should start against Wales in the final test of the year - himself, Dan Carter, Aaron Cruden or Colin Slade, he said: "There's always competition within the squad. We're just training away trying to be better than each other. We all get along with each other. As I say, we're butting heads and are all striving for that number one start. It's an opportunity for me to finish the year off well.
"There are some world class 10s in this team but we leave that decision-making stuff to the coaches."
His answer contained the neatness that his play is becoming renowned for. If he performs well, he will probably keep his nose in front of Cruden. A match-fit Carter, not required for tomorrow, remains the top-ranked No 10, but the competition is growing by the week, something touched on by coach Steve Hansen.
"There's a lot being made of Beauden playing ahead of everybody else. We're very fortunate we've got four outstanding first five-eighths, one of whom has come back from injury and is probably a little bit rusty," Hansen said, in reference to Carter's performance against Scotland.
"If you think about his best form, he's probably not at his best form, but even at half his best he's still a pretty handy player. The other three have been great all year and Beauden is making great progress, but what we need for any five-eighths is front-foot ball, so the contest will be won up front."
Hansen said he was looking for good decision-making from Barrett, who is one of the quickest in the squad and ideally suited to the running game which the All Blacks will look to launch at Wales.
"Your 10 is your main computer. He's the guy that has to absorb all the information that's coming and make the good decisions. He's the guy who will handle most of the ball.
"You want him to defend bravely and use the assets he has got - he's quick and has a good kicking game. But you just want him to use those things at the right time."
Barrett is expecting to have to make some tackles. Wales possess some huge men in the form of George North, Alex Cuthbert and Jamie Roberts and all will try to run down his channel at some point.
"I prepare for that every game," the Taranaki playmaker said.
