Sopoaga's selection at No10 is seismic shock

Lima Sopoaga's elevation to debut tomorrow against the Boks is the greatest All Black shock since the start of professional rugby.

Especially in such an influential role as first five-eighths. A start from the bench was always likely but the decision to pick him in the No10 jersey was an astonishing jolt.

Promotions since 1996 for Richie McCaw, Sam Harding, James Ryan, Isaia Toeava, Aaron Smith and Tom Taylor were bold starting choices and there have been left-field substitutes such as Campbell Johnstone.

But the decision to start Sopoaga is massive when it arrives just three tests out from the World Cup, against the Springboks at Ellis Park.

It's a huge vote of confidence in the young five-eighths, another reminder from the All Black selectors about their continual search for an edge and an in-your-face nudge for everyone in the squad about competition for World Cup spots.

You can think Bob Burgess against the Lions in 1971, Nicky Allen against Wales in 1980 or Andrew Mehrtens' rise to duty in 1995 as brave and exciting five-eighths selections in the amateur era.

Since the players banked wages for their work, the investment in first five-eighths has been more predictable although crises meant Luke McAlister starting against the 2005 Lions and Tom Taylor against the Wallabies in 2013.

Tomorrow's test is not in that emergency category, or at least it did not appear to be even with Daniel Carter resting his match legs back in New Zealand.

Maybe there is a tremor about the mix of 31 players for the World Cup squad. The backline is the mother of all selection headaches, even with Aaron Cruden and Waisake Naholo decommissioned because of injury.

We haven't seen anything of Cory Jane, Nehe Milner-Skudder or Tawera Kerr-Barlow in the black jersey either this season as injury has interrupted their ambition.

Three halfbacks will go, it's a matter of deciding which of Kerr-Barlow, Andy Ellis or Brad Weber joins Aaron Smith and TJ Perenara.

That's a small issue compared to trimming the rest of the backline. The options would scrabble Nigel Richards' gifts for unlocking puzzles.

There are going to be some very unlucky high-quality players who miss out when the squad is revealed late next month and with three tests left and rehab routes through the ITM Cup as well, there may yet be more injuries to impact those selections.

Sopoaga has a massive chance tomorrow to influence the men who matter and take another step in a season of continuing delivery.