On his re-appointment to the role last week, Henry admitted the idea of resting 22 top players during last year's Super 14 and choosing a month of physical work instead of friendlies before the World Cup "was a mistake".
However, Henry has now clarified his position again, blaming the timing of the initiative, rather than the concept itself.
"Pre-season fitness to get ready for a season of rugby is what we're talking about here," he told Radio Sport.
"That is not a mistake - that is essential for players to play top rugby.
"Everybody in New Zealand gets that opportunity apart from the All Blacks because of their programme. We admit that it was a mistake having it during the Super 14 because it caused so much disruption.
"But I think everybody would agree there needs to be a pre-season for professional sports people."