A changed backline sees All Blacks fullback starting at second five-eighths with Ruben Love at fullback, and Billy Proctor preferred at centre.
Coach Jason Holland said playing Barrett at second five-eighths had been an option since the start of the season and would result in more attacking players being on the park.
"We want to make good decisions in attack and defence," he said.
And with the spine of the side selected they should be able to do that. The selection was governed by their need to remember their upcoming midweek game and the player load involved.
Skipper and loose forward Ardie Savea returns to the side and would have an impact. They missed his physicality, and ability to be a menace around breakdowns, in their loss to Moana Pasifika last week, Holland said.
Barrett said it had been a few years since playing at second five-eighths, his last in the position was against the Stormers.
"It's exciting, the training's been good this week and I've been asked to do something for the team and it's something I jumped into," he said.
There was a bit of edge going into the weekend because he knew he would go up against a couple of quality midfield men in All Blacks teammates Anton Lienert-Brown and Quinn Tupaea.
"I felt good [at training], I've got plenty of help inside and outside me so the boys are training well," he said.
After the devastation of their loss to a good Moana Pasifika side last weekend, they want to use that as their launchpad for the rest of their season.
"Hopefully, it galvanises the boys and hurts enough to put on a performance against the Chiefs and the Crusaders the following week," he said.
The team's game plan was evolving, and, at second five-eighths, he would have the ball in his hands a lot, and he enjoyed working with first five-eighths' Jackson Garden-Bachop and Ruben Love.
They had worked on rectifying areas of attack that let them down against Moana Pasifika.
"We can't just focus on last week. We've had a couple of good performances this year, we had an awesome performance against the Blues and we've got some guys coming back into the squad this week so there is some excited guys there," he said.