The hype surrounding the clash between Hansen's World Cup winners and Joe Schmidt's Six Nations champions has been growing steadily for the past 12 months as the consistent Irish have risen to number two in the global rankings.
"It is one and two, so whoever wins will be the best side in the world regardless of rankings," Hansen said.
"They are the number two side in the world and you don't get to play one and two that often when they are in two separate hemispheres, so when they do come about, they become pretty big games.