"But we think it is time to give him an opportunity in the big ball park and see how he goes."
The impending exit of Hore, who is 35 tomorrow, has increased the selectors' search for replacements although they have not been prepared to put someone into the front row or into the squad who was not ready.
"That's why we held on to the two oldies but 2015 I do not see Horey being there and I don't think he sees himself being there," said Hansen.
"At some point we have to make a change and we need Colesy to be ready when we make a change."
The panel chose to start Messam instead of Steven Luatua, because of his impact, experience and in case he reinjured his hamstring and could then be replaced.
The Springboks had big loose forwards but Francois Louw was very good over the ball for a big man and the All Blacks felt they needed someone (Cane) to get over it as well.
"If you were to say to me who is our greatest foe then you'd have to say that is South Africa," Hansen added.
"Both these teams have been one or two (in world ratings) or thereabouts as long as I have been here and that's longer than you get for life for murder, you only get 10 years for murder I think, and I have been here longer than that.
"This is a great rivalry and we respect South Africa immensely, I respect Heyneke (Meyer) immensely and think he is a great man.
"No matter what happens, win, lose or draw we will get together with them in the changing room and have a beer afterwards and the same thing will happen when we go over there."
All Blacks v Springboks
Eden Park, Saturday, 7.35pm
All Blacks: Israel Dagg, Ben Smith, Conrad Smith, Ma'a Nonu, Julian Savea, Daniel Carter, Aaron Smith, Kieran Read (c), Sam Cane, Liam Messam, Sam Whitelock, Brodie Retallick, Owen Franks, Dane Coles, Tony Woodcock
Reserves: Keven Mealamu, Wyatt Crockett, Charlie Faumuina, Steven Luatua, Matt Todd, Tawera Kerr-Barlow, Beauden Barrett, Charles Piutau.
Springboks: Zane Kirchner, Willie le Roux, JJ Engelbrecht, Jean de Villiers (c), Bryan Habana, Morne Steyn, Ruan Pienaar, Duane Vermeulen, Willem Alberts, Francois Louw, Flip van der Merwe, Eben Etzebeth, Jannie du Plessis, Bismarck du Plessis, Tendai Mtawarira
Reserves: Adriaan Strauss, Gurthro Steenkamp, Coenie Oosthuizen, Juandre Kruger, Siya Kolisi, Jano Vermaak, Pat Lambie, Jan Serfontein.