The 25-year-old Savea, who has scored 39 tries in 42 tests, was discarded by Hansen and his fellow selectors for the second test against Wales in Wellington, with Waisake Naholo shifting across the field to take his left wing position.
Additionally, Ben Smith has been moved from fullback to right wing and Israel Dagg earned a recall in the number 15 jersey.
Savea's dumping had been a hot topic among New Zealand's rugby-mad public after an indifferent first test performance in the 39-21 win in Auckland, which only served to highlight the poor form he had been displaying for the Wellington Hurricanes.
Savea was also dropped for one game by his Super Rugby coach Chris Boyd for what was considered to be conditioning issues, but Hansen said the hulking winger was physically sound.
"His weight is good. His skinnies (skinfold tests) are good. He's working hard but he's just a little bit bogged down at the moment," Hansen told reporters on Thursday.
"He's probably trying too hard, to the point where he's over-thinking things (and)... when you over-think things you end up being a roadblock and that's not what we want.
"We want the instinctive Jules and when he's like that he hurts people."
Savea had been suffering from mental fatigue, Hansen added, comparing it to a person working a long stretch and needing a holiday to "recharge the batteries".
The selectors had considered giving Savea the opportunity to work through his issues on the pitch, particularly given the second test was on his home ground, but then decided it would be better to give him a total break.
"When you see them training really well and then they go and have a performance which is clunky and pretty wooden, you can usually tell without being a psychologist that there is something going on," Hansen said.
"It was tempting to play him again on his home patch but he's working on a lot of things so it was felt that it was better that he didn't play."
The third and final test is in Dunedin on June 25.
(Editing by John O'Brien)
