However he went on to explain that it would not affect the match on December 1 at Twickenham.
Kiwi forward Kieran Read explained that he’d recently been sick and that players had a “guided tour of the bathrooms” yesterday, before going on to say he felt a lot better.
“Hopefully it’s a 24 hour thing,” said Read.
“It’s just something you have to handle and we’ll be alright for Saturday.”
After recovering from an ankle injury, Dan Carter has been selected for the team and will start at outside-half.
Hansen explained that Carter has said he’s fine to play, and his performance has also proved the same.
“Hopefully we’ve been smart enough to keep energy tanks full,” said Hansen to BBC Sport
Listen to the game on BBC Radio 5 on December 1, kick off at 2.30pm.