Ian Foster says New Zealand are "hurting" and on "a tough learning curve" after they were beaten at home by Argentina for the first time in Christchurch on Saturday.
The All Blacks had halted a three-match losing streak by beating South Africa at Ellis Park, but the Pumas consigned them to a historic 25-18 Rugby Championship defeat at Orangetheory Stadium.
Emiliano Boffelli booted 20 points and Juan Martin Gonzalez scored the Pumas' only try as they fought back to secure a stunning victory.
All Blacks head coach Foster was backed to keep his job through to the Rugby World Cup in France next year following the win over the world champions in Johannesburg, but this loss put him back in the spotlight.
Foster expressed his frustration over his side's inconsistency following a defeat that leaves them third in the table behind surprise leaders Argentina and Australia.
"[I am] Not losing patience, but certainly hurting." said Foster.
"It's hard work when the team is not, sort of, at 100 per cent every week. But I have been there when it is, and I know how much experience you need to get to that point and how much hard work and how settled the team needs to be.
"For us, as you can imagine, there is a shed full of people that are hurting right now. We are working hard and making some moves in our game.
"Things are hard work at the moment. I thought that at half-time, we had got some really good set-piece dominance. We kept them in the game with what I thought was some pretty average on the offside line.
"We gave them four penalties in that space in the second half."
The 57-year-old continued: "We ended up trying to over-play our hand, really, and got a little bit frustrated against them. Our set-piece didn't quite work the way we wanted in the latter part, and we probably forgot to play our kicking game.
"So, a tough learning curve for this group at the moment."