A former Black Caps captain has issued a warning to New Zealand Cricket over the Trent Boult availability controversy, saying it needs to get ahead of a changing international game.

Ace wicket-taker Boult will miss the two tests against the touring English side next month because he will only return from the UAE T20 tournament just days before the highly anticipated series begins.

Former all-rounder and national selector Dion Nash backed New Zealand coach Gary Stead’s decision to rule Boult out, with Nash saying it wasn’t a straightforward matter.

And he suggested that a sudden call-up for Boult - a free agent since turning down a central contract last year - could cause divisions within the Black Caps.

But Nash said the clash between T20 riches and national duty was a growing problem that needed sorting out around the world, with the obvious answer being to establish specific playing windows.

Cricket bosses around the world needed to act, he said.

“Gary is between a rock and a hard place a little bit,” Nash told NewstalkZB’s Jason Pine.

“There are precedents and probably that conflict as a coach making special allowances for special players which is always a conflict internally.

“The guys in the squad are doing all the hard yards and the work - what happens with Trent coming straight in?”

Dion Nash. Photo / Babiche Martens

Nash said it was also difficult for Stead and co. to truly know if Boult was ready for test action.

He said while world football had evolved to a point where it largely coped with the club v country issue, cricket was still in transition as T20 took off.

“I think it’s the only call Gary can make given the circumstances, but what I would say is it’s a challenge New Zealand will come up against more and more,” said Nash.

“It’s not about rights and wrongs - New Zealand Cricket will have to evolve in how they deal with it, and are probably thinking about it as we speak.

“It will continue to be a tough call and they need a set of principles by which they select. We’re at a tipping point and players are being forced to make decisions.

“Heads of the game [around the world] would be better off getting out in front of this. It’s going to happen more and more.

“[Cricket could] create windows for T20 with little or next to no international cricket on - everyone could have their cake and eat it too.

“Working towards that is better than trying to do something magical like finding more money to pay them.”

Nash said Boult remained an automatic test selection in the right circumstances, but there were other terrific performers at New Zealand’s disposal.

Slipping Boult straight back into the test line-up was not as simple as it sounded, because teams built up cohesive patterns and partnerships.

Boult was making a perfectly understandable decision, for his family’s future.

“Yes, 100 per cent, I can see the attraction of being a freelancer,” said Nash, a famously competitive cricketer.

“It’s even happening for Australian players and even the United Kingdom to some degree. Everyone is aware of it but the answers aren’t easy.”