His numbers don't necessarily roar "pick me" but equally he's shown enough to suggest he is well worth a good look.
Santner has scored two centuries in 20 first-class games, since his debut in the 2011-12 season, averaging 27 from around No 8 in the ND order; and he's nabbed 25 wickets at 55.6.
The 23-year-old averaged 32 in the just-completed Plunket Shield, and 36.22 in the 50-over Ford Trophy, along with 14 wickets.
"It was a bit of a surprise," he said of his selection. "It was my first full season with the Knights playing all three formats. I thought maybe in a couple of years I might get a callup with Vettori retiring."
Funny he should mention the enduring Dan Vettori, whose illustrious career ended in the World Cup final in Melbourne last month.
There are obvious parallels, in the way they bowl and their capability with the bat around the lower-middle order, plus playing for the same province. But there it should end, at least for now.
"He was my idol growing up," the Hamilton university student said. "I managed to play a few games with him two years ago, and it was quite cool being around him."
You'd be a mug not to be a sponge in that situation. Santner said Vettori had talked with him about tactical approaches, how to set batsmen up, differing bowling speeds, at which Vettori was a master, and maintaining patience.
His past few weeks have been spent working with the English Duke balls, which are harder, have a more pronounced seam and can be harder to grip. Santner won't be a stranger in England. He spent a season with the Holmfirth club in the Huddersfield League.
He thinks of himself as an allrounder, as distinct from a bowler who bats handily.
Hesson wants to see him take his opportunity in England. The only other spinners in the squads are both offspinners, Otago pair Mark Craig and Nathan McCullum, in the test and ODI parties respectively.
"Mitchell brings to the table some all-round cover," Hesson said.
"We're hoping he can take his opportunities and continue the excellent progress he's been making over recent seasons."