Ireland could find out on Monday if fly-half Jonny Sexton will be able to face New Zealand this weekend.
Sexton came off at half-time during Saturday's 32-15 defeat to Australia with a hamstring injury and the Irish camp are expecting an update on Monday.
If the prognosis is unclear, Schmidt admitted Ireland can ill-afford to gamble on the 28-year-old Racing Metro playmaker's availability.
Schmidt said: "I guess on Monday we'll find out the degree of his injury and then that will either make a decision easy for us, because it looks good or it doesn't look good.
"If it's halfway in between, then certainly my expectation would be that he would have to train on Friday.
Wear and tear
"He hasn't really spent that much time with us training, he had a little hip-flexor issue plus we left him to rest against Samoa just because of the attritional game time he had already accumulated.
"And I think the wear and tear of that game time has consequences, and unfortunately those consequences have fallen in our lap."
The All Blacks will be without their No 1 fly-half Dan Carter in Dublin, but their likely replacement, Aaron Cruden already has 27 caps, whilst Ireland's options if Sexton is unfit - Paddy Jackson and Ian Madigan - have a combined cap total of 11.
Schmidt admitted that would hand the Kiwis an advantage in a key area: "One of the things is the number of Tests they've played.
"Aaron Cruden's accumulated almost 30 Tests (whereas) Paddy Jackson and Ian Madigan have a handful each.
"That's a very big gap in terms of learning, experience and opportunity to maybe make some errors and learn from them. And they will be surrounded by some experienced players.
"So it's important for us to try to get the right players around the 10 if it's not Johnny."