Carter was ruled out of last night's 21-5 victory over Argentina in Wellington and Cruden was handed the reins. He produced a mixed performance in tough weather in the capital.
The All Blacks were guilty of failing to adapt to the surroundings, particularly in the first half where Cruden struggled to stamp his mark on the game and give the home side the direction they needed.
He grew in to the game though and found his range in the second spell and produced a couple of nice touches, including a great cut-out pass to send wing Cory Jane over for New Zealand's second try.
Hansen said Carter would be available for the trip to Argentina for the return match against the Pumas on September 30 but they decided to pull him early from next week's encounter so he could focus on his rehabilitation.
"He's getting older isn't he? And the more you play the game the more vulnerable you are to injury and he's got quite a few miles on the clock," Hansen said today.
"So that's just standard for any older player and he's got to be smart. We've got to be smart in how we deal with it.
"Just at the moment it's about getting him on the park now. It's as much about that as it is about the long term. He's what we call a 'red-flag athlete'. He's a high risk of getting re-injured so we have to be smart about the wear and tear of his body and how much pressure we put him under."
While young Taranaki pivot Beauden Barrett is also in the squad and has looked sharp during the opening rounds of ITM Cup, Hansen expected Cruden to be given another night in the hot seat.
"To be fair Aaron will probably start."
There's also a chance Cruden may find a different halfback inside him against South Africa after his Manawatu team-mate Aaron Smith was given a rough time by the Pumas last night.
Hansen rarely likes to speculate on his starting line-up so far out from a test given he won't name his match-day 22 until Thursday but said the more calm and collected game of Piri Weepu could be seen in the No 9 jersey in Dunedin.
"We could well be tempted to give him a run, yeah. That's another Thursday question though."
Hansen also confirmed there were no major injury concerns from the side who beat Argentina just general bumps and bruises.
