"Our job is to pick the best team we think can take on the next opposition. That will not change at all. When it comes down to the nitty-gritty, we do what we need to win...if it is someone we need now.
"Where it becomes tougher is if you toss the coin between two guys, and one is staying and one is going and we can't separate them across the skill level. Then clearly, we would favour the guy staying, but I can't remember an instance of that in the last five years."
Fox also indicated that brief 2015 All Black Charlie Ngatai, the Chiefs midfield back who is playing for his club after a long concussion-related absence, might be considered. Fox believed his return to Super Rugby was imminent.
Fox said: "It is a short time frame but he's a class footballer with a great skill set and can play a number of positions. People like that are important when picking a match day 23."
Fox sounded hopeful that Read in particular, and also Kaino, would be ready for the first Lions test, saying their experience meant they would hit top form quickly.
The All Blacks knew their squad would probably be injury affected, had coped before, and would simply "roll up the sleeves" and get on with it.
"We understand the style of game they (Lions) will bring and they are very good at it," he said.
"We've got to make sure we can deal with that, get our up-tempo game going...but we've got to get over the top of them in set piece, or at least manage them.
"We know they will kick the ball well, set piece well, drive well, and have some balance in their game. Gats (coach Warren Gatland) does like to move the ball strategically,in the right parts. They will be hard to break down."