Quite what the Crusaders will do is not clear. Fruean is drifting towards the role of impact player and may decide finally to throw his lot in with Samoa and/or head offshore in search of more money.
They have Ryan Crotty and Tom Taylor who can both play at centre at a pinch.
Canterbury's recent acquisition from Wellington of New Zealand Sevens player Belgium Tuatagaloa may indicate the Crusaders are hoping the 23-year-old is the long-term answer at centre.
The Highlanders have the best manpower but who knows whether they will be able to hold on to Nonu, who only signed for one year after leaving the Blues in 2012. Having been forced out of the Hurricanes and then leaving the Blues in circumstances that left coach John Kirwan less than impressed, Nonu may have no choice but to stay where he is.
Smith has been fiercely loyal to the Highlanders in the past and is thought unlikely to shift anywhere else in New Zealand - the bigger worry is him shifting overseas.
The other congested area will be lock, as the Blues are losing Anthony Boric and hold concerns about the longevity of Ali Williams, while the Chiefs must replace Craig Clarke.
So the recruitment battle is likely to hot up in the next few weeks and activity is likely to be most frantic at the title-chasing Chiefs, who must first lock in their invaluable coaching team.
The defending champions are in the curious position of being rock-solid on the field but a little challenged off it, having lost a long list of senior players that includes Kahui, Clarke, Toby Smith, Lelia Masaga and Brendon Leonard.
Player departures are a perennial hazard in New Zealand and, while the Chiefs will be able to count on their development programme to plug some of the gaps, they will most likely still have to delve into the transfer market to keep their side at the top of the heap.
But before they can do that, they need to extend the contracts of their four-strong coaching team: Dave Rennie, Tom Coventry, Wayne Smith and Andrew Strawbridge. Chief executive Gary Dawson, who will also be moving on after this season, is confident the retention of the coaching staff will be one of his last acts in charge and that an announcement on that front is not far off.
With so many sides looking to bolster their ranks in one position, there is a danger things could turn ugly - that franchises could become overly competitive and lose perspective. That often appears to be the way of things in Australia, where leading players change teams frequently, seemingly always driven by the lure of more cash.
But money is not necessarily a deciding factor in the New Zealand market.
Franchises are allowed to spend only up to $180,000 on any player, with the New Zealand Rugby Union having to top up salaries after that.
The big factor here is the quality of the coaching and facilities, as well as the prospect of regular involvement.
Retention of the coaching staff is therefore critical, says Dawson, as the reputation of the current team is the ultimate recruitment tool: "I don't think there is the same feeling here as there is Australia," he says. "For most players, the question is which franchise will offer them the best opportunity in terms of game time, coaching and facilities."
