Overseas spinners coming to Indian shores might fantasise of the ball turning square, but not New Zealand's Mark Craig.

"The one that goes straight is probably just as invaluable as the ball that turns. I think over here, at times it can probably do too much, so the key is trying and find a way for the ball to slide on straight," he said a week out from the first of three Tests in Kanpur.

Craig is yet to play a first-class match in the country and has not played Test cricket in seven months after a beamer struck his hand while playing for his state side Otago. He has used his time away from the game to make technical changes, he said. All of them pertained to his bowling action, which a spinner relies on quite heavily.

"I was getting pretty flat with the shoulders, trying to get my shoulders back to 45 [degrees, to be taller at the crease] when I load up," Craig said. "Not getting too long in my delivery stride and just closing off with the feet. So just three things that I can always go back and look on now. And yeah, happy with the changes I've made."

His tweaks have come in the wake of two dismal series against Australia last season - seven innings, 137.2 overs and only 10 wickets.

Craig said New Zealand have observed India's spinners to gain insight on how to bowl in subcontinent conditions. R Ashwin was recently called the best in the world by his coach Anil Kumble, and Ravindra Jadeja picked up 10 wickets in a match in the final of the Duleep Trophy - the first-class tournament that kicked off India's domestic calendar in 2016-17.

"They're probably different spinners to our boys, but they're world class," Craig said. "They tend to play around a little bit with, I suppose, undercutting the ball slightly so they get that ball to skid and one to grab. We've done a bit of work at watching how they bowl and at the same time we've got to do what we do."

New Zealand have three spinners in their squad. Craig bowls offspin, Ish Sodhi, legspin, and Mitchell Santner, left-arm spin. Craig understood that there would be a lot expected of them but was mindful of not allowing that pressure to push them into trying too much.

"There's a lot of expectation that falls on you [when] you go into spinning conditions, I think it's key to not try and reinvent the wheel. Just keep doing what our boys have been doing and let the wicket do it for us.

"Those boys have played [in India] a bit more than I have. So [I am] sitting next to them on the bus and talking shop so to speak, just about the paces to bowl and how the wickets generally are like and things like that. We're always talking, pretty tight unit. The chance that a New Zealand side might play three spinners in a Test, if it goes ahead, is pretty exciting."

Craig hasn't ignored his batting. He has three Test fifties and is known for an ability to hang around and frustrate bowlers. "Just trying to nurdle it," he joked in response to a question on whether he's tried to hit his team-mates for sixes. "Keep it on the ground mate, bat longer."

The New Zealanders play their first match of the tour, a three-day game against a Mumbai XI in Delhi, on Friday.