"And all the players know that, I've been there, I know that…you turn up for a friendly you want to play well, there's a bit of nerves.
"But it's not like (the Denmark game)…bearing in mind we are playing the most important game, since I've been back, of this campaign. I want them to be fresh."
McCarthy had little knowledge about New Zealand, whose last match was against India in June last year. They also have a new coach in Danny Hay.
While New Zealand will return to action after a 525-day gap, Ireland has played 14 matches in that period during which McCarthy replaced Martin O'Neill as manager, his second stint in charge.
"We've got to treat New Zealand with the same respect as everyone else," McCarthy said, fairly unconvincingly.
"We'll be looking at whatever stuff our analyst has got, see how they've played in the past and how we think they'll play now, what players they've got and try and get some handle on how they're going to play of course.
"But it's been pretty difficult, there's not that much recent footage out there."
One All White he does know about is in form Burnley striker Chris Wood. The big front man is in excellent goal scoring touch for the EPL side, but he failed to score in eight appearances under McCarthy at Ipswich Town four years ago.
"I had him on loan (from Leicester) at Ipswich, he's a terrific striker, he's in a good run of form as well, he's scoring goals, he's a real handful Chris, he's a good player," McCarthy said.