Ratima or Roigard? GOAT All Blacks halfback Aaron Smith weighs in on the No. 9 debate

One of the hottest positional talking points this year with the All Blacks has centred around who should wear the No. 9 jersey.

Cortez Ratima has continued the momentum from his breakout campaign with the Chiefs with an impressive rookie season to eventually surpass TJ Perenara in the pecking order as Scott Robertson's scrumhalf.

But with Cam Roigard now fit and firing on all cylinders, there's growing conjecture around where each player is better suited - be it as a starter or impact player off the pine.

There's arguably nobody better qualified to comment on the situation than Aaron Smith, a 123-Test centurion widely considered the greatest halfback in All Blacks history.

As was the case last weekend against England, Ratima has been named as the run-on halfback against the Irish in Dublin on Saturday (NZ time), with Roigard backing up off the bench - a role in which he had a significant influence at Twickenham.

Given Roigard's long lay-off and Ratima's emergence, Smith believes Scott Robertson and his staff have struck the correct balance - at least, for now.

"To see Cam back, holy - you can tell how hungry he is with how fit he's turned up," Smith told SENZ's Scotty & Izzy.

"I'm actually happy they have guided him back in and not just chucked him straight in there, because Cortez has earned that right this year.

"He had a great Super Rugby and his ability at the Test level is just showing."

Having gone toe-to-toe with the Irish on several occasions over the past few years, Smith is all too familiar with the way Ireland coach Andy Farrell likes to pull the strings and types of opportunities both Ratima and Roigard will have to unlock his notoriously stout defence.

The 2015 World Cup winner's ability to snipe around the fringes was a key component in the All Black's famous quarter-final win against the men in green in Paris last year.

But Smith's advice comes with one clear word of caution.

"The way Ireland defend, they have a guy close to the ruck, but then they're very spaced out and zonal," Smith explained. "So, there are opportunities to run if we're able to get good go-forward football, but also chances to put people away.

"The only scary thing is that, as a No. 9, if you get caught against Ireland, (flanker) Caelen Doris and the likes just steal the ball.

"You've got to be quite careful that, when you try to take an opportunity, it better be a good one, otherwise their defence is so good that they will punish you for it.

"There are little creaks around the ruck, which is exciting. Those boys have got a bit more go-go juice than me, but I was able to find a few last year, so it's just around picking your moments, playing on top, keeping the ball moving and making sure you've got support with you."

Listen to the full interview below: