McCullum, Luke Ronchi, Corey Anderson and Martin Guptill have played each of the six games so far in this series, including the wash-out in Auckland.
Batting coach Craig McMillan hinted rest and rotation would form part of the build-up, particularly with a view to giving Tom Latham an opportunity as a back-up opener and wicketkeeper.
"It is a possibility," McMillan said. "Most of the players have had a bit of a rest. It's something we planned to do throughout the series. There's still a bit of cricket [three ODIs and two warm-up matches] before the World Cup, so it's important everyone gets a game off to freshen up mentally.
"We're pretty comfortable where Brendon's at. He's more than happy to sit the odd one out and let Kane take over [as captain].
"Tom is the likely replacement. He can cover any batting position from one to six, but it's likely he'd go to the top of the order."
Rest and rotation tends to generate pangs of anxiety for New Zealand sports fans whose memories recall the policy's use during the All Blacks 2007 Rugby World Cup failure.
For the New Zealand cricketers, it might present a risk to momentum as the World Cup looms but, given it's only likely to be for one or two games, it could be a prudent measure against staleness.
McCullum had some time off after the wins in Dunedin, including a visit to the Karaka yearling sales to pursue his racing passion. He was due to rejoin the team last night after missing training.
If he's omitted today, it's likely he'd return against Pakistan on Saturday to appease the Wellington cricket faithful - perhaps at the expense of Guptill - and Wellingtonian Ronchi might rest out the following game in Napier to familiarise Latham with the keeping gloves.
With Elliott resurrecting his place in the starting XI as a batting all-rounder at No 5, Latham becomes the equivalent of rugby's utility.
"We want to give guys time in their roles and Grant's taken those opportunities with his performances over the last few matches," McMillan said.
Elsewhere, Mitchell McClenaghan has played five of the six games, more than any other pace bowler, and Adam Milne could return as early as Saturday from his side strain after appearing to coast through a fitness session.
McClenaghan might expect a rest soon. Tim Southee has completed only two matches after not featuring in Auckland due to rain and Kyle Mills returned for the second Dunedin game.
Intrigue also surrounds the selection of the spin bowling all-rounder for the coming games. Nathan McCullum and Daniel Vettori have each played nine ODIs this summer - and four this series - although McCullum missed a chance to contribute due to inclement weather at Eden Park.
In the Sri Lankan camp, pace bowler Lasith Malinga trained as he recovers from his ankle injury but will be rested today, according to stand-in skipper Lahiru Thirimanne.
There was nothing hesitant about his power hitting from the middle of the Basin Reserve during practice. One shot cleared the sightscreen and bruised the chest of team manager Michael de Zoysa with a surprise direct hit.
Angelo Mathews has recovered from his calf injury but is now beset with flu and spinner Rangana Herath has returned home to deal with a family matter. He's expected to return next week.
Thirimanne said the focuses for his side would be on middle order batting and death bowling with the series ledger sitting at 4-1.
- By Andrew Alderson of the New Zealand Herald
