He showed encouraging signs in the three-day tour match last weekend when he picked up 3-65 against the West Indies Cricket Board President's XI, which punched his ticket for the big dance.
There was little time to sit around before he got in to the action, though, thrown into the fire when he was sent in as a night watchman late on day one of the first test against the West Indies. After arriving in the middle of a sharp spell of spin bowling from Sunil Narine, Wagner survived until the close of play.
The 26-year-old went wicketless on day two at the Sir Vivian Richards Stadium in Antigua but showed promising signs of what is to come.
Aside from the endorsement from Vettori, Wagner ran in hard all day and the left-armer looked the most threatening of the Kiwi bowling attack and had a couple of decent lbw shouts turned down late in the day.
The West Indies closed day two on 145-0 with openers Chris Gayle (85) and Kieran Powell (58) unbeaten at the crease.
Gayle, who recently returned to international cricket following a long-running dispute with the national body, was put down by Daniel Flynn when he was on 36 from the bowling of Doug Bracewell.
"Like I said, we can't give those freebies away away to Gayle, because he's like a [Virender] Sehwag," Vettori said.
"He'll just really hurt you and we were at sixes and sevens pretty early on and it puts you on the back foot. You had to bowl to defensive fields and you probably don't bowl as well as you'd like, so that was pretty disappointing after what was a reasonably good batting performance."
Earlier on day two, New Zealand resumed their first innings on 232-4 but failed to produce another major partnership as their middle and lower order all got underway but couldn't kick on a significant score.
They looked shaky at 309-9, but Bracewell and perennial batting bunny Chris Martin slogged 42 for the final wicket - Bracewell finished with 39 from 31 balls - to push the New Zealanders to 351.
Narine was again a burden for the visitors, with the spinner claiming 5-132 from 43 overs.