Wales had taken a game off South Africa in July to give them confidence. The All Blacks were aware of that, but they would concentrate on continuing their improvement from the Rugby Championship.
"We're at a stage where we're looking at ourselves, where we're looking to get better from the Japanese game, and towards the end of the week, we'll start looking a little bit more at what they're going to bring.
"No doubt they'll be staunch. They're a fit side, they like to play a lot of rugby. We'll be up for the challenge, but at the moment we're just focusing on ourselves."
He expected that in regular first five-eighths Dan Biggar's absence, New Zealander Gareth Anscombe would play. They played together in the New Zealand Under-20s side that won the world championship in Italy, and Barrett knew he was a confident player who was injury free, who would be looking to perform well against the All Blacks.
Barrett said his appointment as co-vice-captain with Ardie Savea didn't change anything. He had had the position before, and it would be business, as usual, for him.
With Sam Whitelock taking over the captaincy role in Sam Cane's absence, Barrett said he led through his preparation, his actions, and how he performs on the field.
"He's been around a long time and has plenty of experience and stories. We're gutted to lose Sam Cane for the tour. He's a different leader - whilst he still leads by example, he is a great communicator.
"We're well supported in the leadership group, and we're fully supporting Sam Whitelock and it's great that Ardie [Savea] and I can be v-cs [vice-captains]."
Barrett said while there were disruptions before leaving New Zealand, the management had done well with the core of the team settled, with moving parts around it.
Now they are on tour, things should be more settled, and they were looking forward to playing the Welsh while enjoying being back in Britain.
Upon reflection of the weekend's game against Japan, he said they felt the Brave Blossoms were a side that needed to be respected.
"It just goes to show every Test match anyone can win on the day. We've got a lot of room for improvement there so we highlighted areas in our review where we need to be better because it's going to be another step up back here at Principality Stadium against a hungry Welsh side."
Wales would have their eyes on the All Blacks and achieving their first win over them since 1953.