Australian leg-spin bowler and spin coach Terry Jenner says New Zealand's young spinners need to be more aggressive in their approach.
Jenner was in Christchurch last week to conduct his annual spin clinic, having earlier conducted a coach the coaches session in Palmerston North.
Compared to previous visits to New Zealand he felt the finger spinners were on a par with expectations while in the wrist spin department there were two or three players who were improving all the time.
"They've just got to work harder.
"I told the finger spinners that. If they want to take Daniel Vettori's place in the national side they have to ask themselves why Glen Sulzberger has the place in the team and they haven't?"
The work ethic is a part of Jenner's coaching method, which sticks to the basics of the spin craft.
He believes the hunger factor is a notion that could be applied to New Zealand's performance, especially in the Test matches against Zimbabwe.
"It is no good playing cricket by waiting for other people to do things. You must demolish teams like Zimbabwe.
"It is no good saying that weak teams drag you down to their level. Good sides rise above weak teams," he said.
Jenner was unimpressed with New Zealand's approach in the Tests and said the only difference between the two Tests was Chris Cairns' batting in the second Test.
"He is the shining light in the team and he's got to take the game by the scruff of the neck," he said.
In relation to Zimbabwe's 2-1 defeat of the CLEAR Black Caps in the One-Day International series Jenner said: "Zimbabwe can beat you once, but not twice."
"The hunger is there when a top team starts to steam roll weaker sides."
Jenner said it was a tragedy that Vettori had broken down in the first Test. On the one hand if you were playing international cricket you can't put in a limited workload for a player but you could monitor the work that was being done.
Vettori's action looked as good as it had ever been but he did notice that while Paul Wiseman was getting a lot of spin in the match Vettori wasn't and wondered then if everything was right.
"Watching Paul Wiseman I was pleasantly surprised with how he was bowling. Side on his bowling technique was absolutely beautiful.
"But I noticed he didn't bowl well to left-handers and I think that was because his approach lines are a little skew-whiff. When he bowls around the wicket he starts at the same spot as he does when he bowls over the wicket.
"He needs to move his marker and he could do very well if he can bowl around the wicket as he does over it. He will need to do that in South Africa," he said.
Jenner has now become something of a spinning envoy travelling the globe passing on the good oil about the craft, especially the wrist spinning craft. He has regular contact with England, New Zealand and South Africa and recently has been working with chinaman Paul Adams in a bid to help him regain his best touches.
"I enjoy my work wherever it is but I always love going to New Zealand," he told CricInfo from his Adelaide home.
"I find everyone there is pretty receptive to what I am teaching, which are the basics of spin bowling. But there is a willingness to take on board anything that is offered," he said.
Jenner said he had a concern that with all the modern emphasis on dietary matters, psychology and physiology.
"While they are all important I believe that skill is still the No 1 thing. You go to some of these sessions nowadays and just about everything else takes place before the players get into their skills work.
"Of course, you must always keep moving forward but you must never substitute the gift that people are born with."
Dealing with players' gifts is what is most important to Jenner.
"As a coach I break 'gift' down like this - G is for guidance, I is for information, F is for feel and T is for trust.
"What I come out with has stood the test of time. I believe in sharing knowledge, no matter who you are dealing with in whatever country. But you don't give away anyone's secrets," he said.
Jenner felt it was great that Dennis Lillee could run pace bowling clinics, that people could send spinners to work with Indian Bishen Bedi and that he too, could work with people anywhere around the world.
When he is coaching, and especially when he is returning to update players he has previously worked with, Jenner makes the point: "You can't remain the same and improve."
Every day had to be interesting but something more had to be done as well to get the best out of bowling, he said.