Joey Carbery has the attributes to "do what's right" for Ireland at fly-half while showing his full range of skills against Argentina on Sunday, assistant coach Mike Catt says.

"Rugby's about decision-making and that's all they have to do," said Catt.

"Just make the right decisions and then bring their X-factor on top of that."

Catt added: "Joey, he's very good and it's just making sure we get the right platform for him to be able to show his point of difference. I think that's crucial for us."

Carbery's nerveless three late penalties sealed Ireland's sensational 29-20 win over the All Blacks and Catt says Sunday's game offers him another chance to show that the Irish now have genuine depth in their fly-half ranks in addition to 101-times capped Sexton.

"I never worked with him when he had his best [form], so I'm still learning about Joey myself," said Catt.

"But over the summer and the past three or four weeks we've had together, him and Harry [Byrne] and Johnny have been exceptional in how they've progressed, in how they've helped each other and how they're competing against each other for those spots.

"It's a very, very healthy environment for that to happen.

"He's hopefully going to get a few opportunities tomorrow to really do what he's good at and go out and enjoy himself."

Catt says Carbery has a different personality to Sexton, whose leadership and intensity are fundamental to the Irish side.

"They are very different characters but you need that in a team. That's what makes you a good team," said the 50-year-old former England international.

"Where Johnny's leadership comes through, maybe Joey doesn't have that just yet.

"But other people bring that, so it's just making sure that you bring what you are good at and we will grow the other aspects that need to be grown as a 10.

"If everybody is helping you and everybody else is doing their job and leading in their own way, then it's very easy to do."