Who is next in line to All Blacks halfbacks Tawera Kerr-Barlow, left, Aaron Smith and TJ Perenara?

OPINION: The wait to discover who will replace Tawera Kerr-Barlow continues.

When All Blacks coach Steve Hansen announced he would rotate his squads for the final Rugby Championship tests against Argentina and South Africa, it seemed the chance for the selectors to integrate a new halfback, given Kerr-Barlow would join French club La Rochelle at the end of the year, was there to be exploited.

But a cautious approach knocked that idea out of the ball park.

REUTERS All Blacks halfback Tawera Kerr-Barlow is in his final year of playing in New Zealand.

While forwards Sam Whitelock, Brodie Retallick, Sam Cane and Liam Squire and backs Beauden Barrett and Ryan Crotty were permitted to miss the test against Argentina in Buenos Aires, allowing them to fly directly to South Africa for the match against the Springboks, the status quo remained for the halfbacks.

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Kerr-Barlow has again been asked to back up Aaron Smith and TJ Perenara, something he has done all year.

Given three All Blacks No 9s are also likely to be picked for the northern tour at the end of the season, there is plenty of merit to the concept of replacing Kerr-Barlow then. Yet the selectors don't appear to be sold on that, either.

This is a strategy that has its share of pros and cons. Kerr-Barlow, who has played 26 tests since his debut against Scotland in late 2012, offers value in terms of experience if Smith or Perenara get injured.

But by sticking with the status quo, the All Blacks are not generating any new talent. They certainly don't seem to be in a hurry to do that.

No plan is without its flaws. NZ Rugby are still undertaking an investigation into Smith's private affairs in relation to off-field issues that were published by an Australian newspaper last month.

The outcome of this could potentially have some impact on his availability for an organisation that is extremely conscious of brand image.

There is no doubt that Smith, who is contracted through to 2019, is the undisputed king of the New Zealand halfbacks. It's what happens away from the paddock that needs to be sorted. The contract for Perenara, who preferred the unusual option of re-signing with NZ Rugby for just one season last year, is up for renewal. It's expected he will ink a fresh deal, with the 2019 World Cup looming.

If he doesn't? Well, that wouldn't be ideal at all.

The logical question to ask right now is who is in line to replace Kerr-Barlow.

Blues and Counties halfback Augustine Pulu got two test caps in late 2014 when Kerr-Barlow was recovering from a serious leg injury. The following year, with Kerr-Barlow fully recovered, Pulu was cut loose.

Instead Brad Weber burst on to the scene, his fast pass earning him his first and only test cap as a replacement for Andy Ellis against Samoa in Apia in 2015. Come the World Cup title defence later that year, it was Smith, Perenara and Kerr-Barlow who were selected. It was the same story last year.

But when Kerr-Barlow leaves for France the selectors' hand will be forced.

Pulu and Weber, who played no part in Super Rugby this year after breaking his leg in the Brisbane 10s, are options. Crusaders halfbacks Bryn Hall and Mitchell Drummond would be worth a look.

The NZ under-20 grade side has proved a decent breeding ground over the years. Sam Nock and Te Toiroa Tahuriorangi, who played for the age-group side in 2016 and 2015 respectively, have been integrated into Super Rugby.

Earlier this year Canterbury's Ere Enari, who made one appearance as a substitute for the Crusaders, was the vice-captain of the NZ under-20 side that won the world title in Georgia.

The smorgasbord of No 9s has been unveiled to the All Blacks' selectors for some time. It's just their succession plan that remains under wraps.