New Zealand begin their Rugby Championship title defence against Argentina on August 10, before tackling South Africa and Australia.
Harry Plummer, who plays first five-eighth for the Blues in the Super Rugby Pacific tournament, was added to the squad after an injury to Stephen Perofeta.
Barrett injured a finger during the All Blacks' 47-5 win against Fiji in San Diego, which needed surgical treatment after his return to New Zealand.
Assistant coach Jason Ryan announced the changes today at the team's base, the NZCIS sports facility in Upper Hutt, near Wellington.
Ryan said that the All Blacks have "definitely got to build up from where we left off pretty quickly" after three wins to start the season.
"Argentina bring a different intensity to the first three tests that we had… it should be a good contest, they've been playing really well," Ryan said of Pumas, who split a series 1-1 with France and demolished neighbours Uruguay in their three tests so far this year.
"I think they've always been a passionate side, they play with energy and momentum. (Matias) Kremer and (Pablo) Matera are big around the breakdown."
Ryan said the focus now that the squad had reassembled for the Rugby Championship was to adapt to challenge that the Pumas, Springboks and Wallabies would pose.
"You've always got to be evolving your game, week to week. We're always trying to tweak things."
As for what the biggest work on was after the two recent victories against England, Ryan pointed to the breakdown.
"We learned a lot around our carry and clean game. We were really accurate around our decision-making, we're looking forward to building off our scrum and set piece.
"We've got some good lads who made contributions in our loosies, our locks are a competitive area… yeah I think we've got a lot of confidence in everyone. It makes selection meetings a bit tastier."
The All Blacks and Argentina are set to announced their teams on Thursday.
Papali'i re-signs with NZ Rugby
All Blacks loose forward Dalton Papali'i has re-signed with New Zealand Rugby through to the 2027 Rugby World Cup, NZR confirmed.
The 26-year-old, who has played 34 tests, also extended his contract with the Blues, based in Auckland.
"Dalton is a world class loose forward who brings physicality and work rate on both sides of the ball and can play multiple positions," All Blacks head coach Scott Robertson said in a statement today.
"He works hard every day in our environment and continues to grow as a leader and player. Having Dalton in New Zealand for the next three years is a great result.”
Papali'i said it was an easy decision to remain in New Zealand.
"I’m loving my footy right now at every level and home is where the heart is."
All Blacks v Pumas
Kick-off: Saturday August 10, 7.05pm (NZ time)
Sky Stadium, Wellington
- additional reporting by Reuters
