In the final training run for the test in Cardiff, the first five felt some pain in his right leg when kicking and was taken away for further assessment.
Carter appeared to hurt his leg earlier in the week, as reported by the Herald, but before today's run there were denials about any problems.
When questioned at the team announcement, coach Steve Hansen was emphatic there was no issue with the champion five eighths.
However it did seem unusual that Carter's projected appearance for interviews did not occur with some excuse given about some conflicting task.
After the All Blacks practice, Hansen sent out a note which said Carter had felt a twinge in his leg when he was involved in some kicking drills during training.
He would be assessed by the medical staff in the next 24 hours and a decision on his involvement in the test would be given at the captain's run.
If the medical staff and Hansen deliver the same message they did to hooker Keven Mealamu when he damaged his calf against Italy, they will withdraw Carter from the test.
They have a 32-strong squad and do not want to risk anyone with injuries or are struggling with ailments or damage at the end of a long season.
If Carter does not start his place will go to Aaron Cruden because the other five eighths Beauden Barrett has been guarding sore ribs this week.
Any news like Carter's defection will buoy Wales who are searching for their first win against the All Blacks since 1953.
