The South African-born left-armer cut his end-of-season holiday short to start preparations earlier than normal when he got the welcome news in April that he was finally eligible to play for his adopted country.
Two weeks later he was named in the Black Caps test side for the tour of the West Indies.
He departs for Antigua on Friday and hopes to be named in the side for the first test which begins on July 20.
The 26-year-old should have an edge over his competition for a test spot.
He has basically been preparing for his debut for the past four years and more immediately has had the advantage of bowling on grass while training in Pretoria with fellow South African-born Black Cap Kruger van Wyk.
"I've been training on grass since April, so that has been good," Wagner said.
"Also Kruger van Wyk came over about four weeks ago, so we've been training together and have been pushing each other.
"We also got a couple of good club bowlers to come and bowl to us in the nets, as well, to prepare specifically for what we can expect in the West Indies."
Part of preparation included experimenting with the Dukes cricket ball which will be used in the test series. New Zealand Cricket sent him a supply and Wagner was pleased to report he was able to get the ball to swing.
That is good news because conditions in the Caribbean are not expected to offer much bounce or pace.
One of the reasons Wagner was selected is his ability to get the old ball to reverse.
He used that skill to wonderful effect when he took five wickets in one over during a Plunket Shield fixture against Wellington in Queenstown in April 2011.
It was the first time someone had taken five wickets in an over and it created world-wide headlines.
"I don't think there will be a lot of bounce in the wickets over there and it is going to be really slow.
"So at the end of the day it will be about bowling smart.
"But I think there will be a bit of swing, especially if there is cloud cover around. We're using Duke balls.
"That's something new and I've been training with them for the last three of four weeks.
"They do reverse so that has been looking good.
"The wickets over there are quite abrasive, so if it reverses it will be a key weapon."
Scuff the ball up on one side and maintain the other then?
"Exactly."
As far as analysing the batsmen Wagner is likely to come up against, he said he tried not to complicate things too much.
Dashing opener Chris Gayle has not played test cricket since December 2010 but has declared himself available.
Bowling to the aggressive left-hander would be a daunting prospect but an opportunity Wagner said he would embrace.
"You want to test yourself against the best," he said.
"I try not to over analyse.
"I'll look at a couple things and talk to guys but I don't want to be running in worrying about what the batsman might do.
"As soon as you do that he is going to have the upper hand.
"For me, it is about going out and playing my game.
"It is going to be a fight and a battle and that is what I like."
