From the tail end of 2016 through all of 2017, Savea stagnated, regressed even as a test openside – unable to keep himself over the ball or knock others off it.
Collision football was proving not to be his thing and when he extended his contract in April by just 12 months, it was a sign that even he was losing in his faith in his ability to be the sort of No 7 who can dominate tests.
But since Savea was dropped in late to play No 8 in Buenos Aries, everything has changed. He was man of the match against the Pumas in an unfamiliar role and what shone was not just his appetite to be involved in collisions, but his ability to win them.
A week later and he was the star of the show again in Pretoria: first winning the critical turnover that earned the All Blacks the penalty they kicked deep into touch, and then burrowing his way through the Springboks for the winning score.
Savea, in the exalted company of David Pocock and Michael Hooper, was the best loose forward on view in Yokohama and again it is his physical presence that is impressing.
He says this new found confidence is not connected to physical growth – as he continues to play at a relatively light 103kg – but mental growth.
"I am enjoying it at the moment, going out there and backing myself. I am just enjoying my footy," he said.
"I guess in the past I was probably trying to do a bit too much – on the field and in my head. I have found a way to simplify things and I'm now going out there and playing instinctively what is in front of me."
Not that it was ever particularly in doubt, but Savea has almost guaranteed himself a spot in the All Blacks World Cup squad by playing as well as he has, but also by showing his versatility.
The next question he has to ask is what might his future look like after the World Cup? Will he be confined to cameo appearances off the bench as he was for most of the period between 2016 and September 2018, or can he see a future as a regular starter, building an impressive All Blacks legacy?
He needs to come up with the answer reasonably soon because French club Pau are understood to be chasing him with a mega-bucks deal, and they and New Zealand Rugby will want Savea to have his contractual position post-2019 sorted early next year.
"Obviously I am in the process of making a decision about my future but at the moment I am just trying to worry about this tour," Savea said. "After the tour finishes I will start to think about my future."
One man who is in no doubt about what Savea should do is Steve Hansen.
The All Blacks coach picked Savea as an apprentice back in 2013 and has never doubted that one day, the 25-year-old would find his feet in test football.
"He has made a lot of progress," Hansen said. "He himself would say that he has probably not over thinking the game as much as he was. He is just going out and getting his structures right to play well and he's doing it week in week out.
"He's taking a lot of confidence from being able to be out there for long periods of time rather than just little stints which appears to have helped him build his confidence. He's going really well."
