The time for change may have passed the Blackcaps brains trust by, with the Cricket World Cup opener against Sri Lanka fast approaching.

New Zealand have just five more ODI's before the tournament begins in England in June. The two dead-rubber matches against India will be followed by a three-match series against Bangladesh in February.

Gavin Larsen and his selection cohorts, including coach Gary Stead, have made two changes for the trips to Hamilton and Wellington, with Jimmy Neesham and Todd Astle replacing Ish Sodhi and Doug Bracewell.

But former national skipper Ken Rutherford believes there are more pressing concerns. Martin Guptill and Colin Munro have scored just 79 runs between them in the first three games, piling immense pressure on the star-studded middle order of Kane Williamson, Ross Taylor and Tom Latham.

Munro's position, in particular, is under serious threat, with the left-hander only averaging 22 in the last 18 months, passing 50 just twice.

Rutherford is cautious to throw too much criticism in Munro's direction, given it's unclear what the Aucklander's role is.

"If he is being asked to be a bit of a basher, and have a crack up front and wield the willow, then you have to expect he is going to fail more often than not," Rutherford told Newshub.

"But if he is being asked to play the role of a batsman, then he is probably not the right guy. You need a more conventional type of batsmen, like a Tom Latham or a Will Young.

"The question needs to be asked of Kane Williamson, Gavin Larsen and Gary Stead: 'What is the role you are asking Colin Munro to play?'

"If that role is to score quickly, yes, it isn't coming off for him, but he is doing his best and he is trying to fulfil that role."