The All Blacks are seriously considering taking only two halfbacks to the Rugby World Cup.

Coach Steve Hansen admits the option of versatile back Colin Slade covering the specialist position is being debated by the selectors as they try to shoehorn a host of backline options into their 31-man squad for the tournament beginning in September.

Aaron Smith and TJ Perenara are both certainties, with Tawera Kerr-Barlow and Andy Ellis the other halfback candidates.

Kerr-Barlow is likely to stake a late claim in one or both Tests against Australia over the next fortnight, having played the last of his 15 internationals against South Africa 10 months ago when he badly injured his knee.

Ironically, it was Slade’s sound performance out of position at halfback in the closing stages of that loss in Johannesburg which planted the seed of a potential selection gamble.

“Slade is an option after what we saw in South Africa, that is one option we’ll mull around,” Hansen said.

“There’s a risk that goes with that, and it’s just whether we decide to take that risk.”

Kerr-Barlow was solid but unspectacular in his return for the Maori All Blacks last month but has done enough to usurp veteran Ellis in a slightly altered squad of 41 to prepare for both Bledisloe Cup Tests.

Ellis, who started in the win over Samoa in Apia, now looks a World Cup long shot.

Taking two halfbacks would ease the selection headache in some other positions, most probably five-eighth where Lima Sopoaga’s excellent debut against the Springboks last month could see him join Dan Carter, Beauden Barrett and Slade in the play-making contingent.

Another with plenty at stake is two-Test prop Nepo Laulala, who is pushing hard for the injured Charlie Faumuina’s (neck) World Cup tight-head berth.

Hansen says Laulala and Kerr-Barlow shouldn’t try to take on too much against the Wallabies.

“It’s a fallacy that players have to go out and do something special because if they try and do that, they don’t,” Hansen said.

“They force it and it doesn’t fit – I think Aaron Smith will tell you that about his performance against South Africa.

“He hadn’t played for ages, got really excited and he was going to go out and prove to the world how good he was. But everything was a bit scratchy and mistimed and … it was a great learning curve for him.”