All Black legend wants coach Dave Rennie to emulate Rassie Erasmus' bravery

The 62-year-old will name his squad following the Super Rugby Pacific final, which sees two New Zealand teams, the Hurricanes and Chiefs, go head-to-head.

Rennie, who replaced the sacked Scott Robertson earlier this year, has a number of selection dilemmas, but Kirwan wants him to follow Erasmus' lead.

As Springbok boss, he has been at the forefront of the sport's innovations and that has resulted in back-to-back Rugby World Cup triumphs.

Robertson, in contrast, was criticised for his conservatism, a trap the All Blacks legend hopes the new head coach doesn't fall into.

"People probably say that Rassie is a great coach and he is, he is the best, but what people probably don't understand is the courage that it takes to change things in our game – he's done that," Kirwan said on the Rivals podcast.

"Picking a different Test team every week, you wouldn't have done that three years ago. The Bomb Squad, as much as I bloody hate it - I hate the Bomb Squad, actually hate it with a passion - it works, the majority of the time it works.

"Having that courage is really, really important. What we probably do want to see from Dave Rennie is that courage and the public need to support that courage as well.

"Some of the risks that Rassie has taken around some of those selections - changing the Test team every week. This week against the Barbarians, if you play your young guys you learn a lot but it also takes a lot of courage."

As for what Kirwan expects to see from Rennie, he will be surprised if the All Blacks boss manages to completely revolutionise their game plan due to the lack of time until the World Cup.

However, the former wing predicts that the ex-Wallabies head honcho will be bolder in selection than his predecessor.

"I think you will get a core of experienced All Blacks that will be picked [from the Chiefs and Hurricanes]. You should see a lot of those two sides," he said.

"What I'm thinking about is, what has Dave Rennie got in mind? It's not ideal for him coming back this late.

"I don't think he will be too expansive just because this is a 15-month plan; that's all we've got. We've got a massive rivals tour [in South Africa] and then we've got the rest of this year, but really it's about the World Cup.

"I'm really intrigued. I don't know what Dave Rennie will do and I think that's the suspense. Last year or the year before when we saw Razor get in, we thought he might branch out a wee bit. He didn't; he was conservative, so this is going to be a really interesting selection.

"I think that he will [be bolder], I think he will have four or five players where you go, ‘wow'. I think he will go for bolters."