The first test starts at 10pm tonight (NZ time) and the tourists will be missing some familiar faces.
The preparation has not been perfect, either.
Some of the key players arrived in England late and the Black Caps slumped to a seven-wicket loss to the Counties Select XI in their last warm-up game.
Wagner saw that result as largely irrelevant.
He described the preparation leading into the first test as "pretty good", adding that while people will view the loss at Chelmsford as a worrying sign, "it was more about getting miles under everyone’s legs and just getting valuable time out in the middle".
Good hit-out or not, that will do precious little to alleviate a lingering sense among some fans the team has crested the hill.
Test losses at home to Bangladesh and South Africa during the summer led to expectations slipping a fraction.
Then there are the absences and a form question mark.
Middle-order batter Henry Nicholls (calf injury) is in doubt for the first test, and left-armer Trent Boult is very unlikely to play as well.
Ross Taylor and BJ Watling have retired since the last tour to the United Kingdom.
Captain Kane Williamson has not played test cricket since the first test against India in November. The 31-year-old right-hander made a nine-ball duck against the Counties Select XI and had a poor IPL.
And the Black Caps’ tail looks awfully long without Watling to nurse them through.
That said, there are still plenty of experienced campaigners in the line-up, including Wagner, who is ever the optimist.
And there is nothing like the sight of a green blade of grass or two to get the left-armer’s pulse racing, even if it is imagined.
"In the two days we’ve spent at Lord’s there has been quite a bit of rain.
"During our training [session], and as they were about to mow the pitch, it start raining and the covers went back on, so we haven’t had a true look at it.
"But it is meant to be a good couple of days leading into the test."
Wagner has taken seven wickets in two test at Lord’s and said it was always exciting to play at the home of cricket.
The three match series against England was something different as well. The Black Caps usually get stuck playing a two-game series.
Adding to the excitement, there has been a couple of key changes in the English ranks.
England has named former Black Caps captain Brendon McCullum as test coach and New Zealand born all-rounder Ben Stokes as captain.
Those appointments are expected to inspire a bounce in form.
"It is going to be weird seeing him [McCullum] in an England cap when I walk past him.
"He has been an amazing team-mate and mentor for many years now, but he is in the opposition team and he knows us really well, he knows us inside out.
"That is something, I guess, that is a slight advantage to them."
First test
Lord’s, 10pm tonight
New Zealand: Tom Latham, Will Young, Kane Williamson (captain), Devon Conway, Daryl Mitchell, Tom Blundell, Colin de Grandhomme, Kyle Jamieson, Matt Henry, Neil Wagner, Tim Southee, Ajaz Patel, Cam Fletcher, Michael Bracewell, Trent Boult, Henry Nicholls.
England: Alex Lees, Zak Crawley, Ollie Pope, Joe Root, Ben Stokes (captain), Jonny Bairstow, Ben Foakes, Stuart Broad, Jack Leach, James Anderson, Matthew Potts, Harry Brook, Craig Overton.
