New Zealand's summer could have turned sour if they had let victory slip away in Christchurch. In the end, though, Trent Boult and Tim Southee found their yorkers and the series is level heading to Wellington. It could be a fight to the finish.

However, with eyes on the Champions Trophy, New Zealand have some decisions to make and they chiefly surround the top order. Martin Guptill has yet to recover from his hamstring strain so there is an unchanged squad for the third one-day international on Saturday, but when fit he clearly slots straight back in at the top.

The question is, who is alongside him? Tom Latham is in the midst of a lean run: since his 137 against Bangladesh he has made scores of 22, 4, 7, 0, 0 and 2 - the last of those when he flicked an innocuous delivery to square leg in Christchurch.

Currently, Latham also has the gloves ahead of Luke Ronchi. In the first two matches of this series this has helped New Zealand accommodate Ish Sodhi as the second spinner and he has impressed in both outings. In Christchurch Latham kept neatly and was involved in three key wickets: JP Duminy's stumping, David Miller's outside edge and a good catch, coming forward, to gather AB de Villiers' under edge.

But if he isn't scoring runs then the benefit of the balance he provides starts to be negated. Particularly as in December Ronchi was billed as the premier limited-overs gloveman. "At this stage we see him as the best ODI gloveman in the country," selector Gavin Larsen said when Ronchi was recalled for the series against Bangladesh.

However, it isn't a simple case of switching Ronchi for Latham. Although Ronchi was used as an opener early in his ODI career, that ship has sailed: he has a top score of 22 from seven innings opening the batting (a brief return there in the second T20 against Bangladesh brought a first-ball duck). He would need to slip into the middle order, alongside allrounders Jimmy Neesham and Colin de Grandhomme.

That could be an option in England, where a second frontline spinner may not be required during June when the Champions Trophy will be played. However, if both Neesham and de Grandhomme play ahead of another specialist bowler they would need to fulfil most of their 10 overs. It appears a luxury for New Zealand to have the No. 8-ranked ODI bowler, Matt Henry, sit on the sidelines.

Mike Hesson indicated Neesham, who made an unbeaten 71 off 57 in Christchurch, and de Grandhomme will continue to feature together. "Jimmy was excellent, he was one of the ticks we've been looking for," he said. "De Grandhomme in the previous game showed how good he is at finishing. We are starting to answer a few questions around the balance of the side and Jimmy's innings was really important in that."

If Latham's form does not improve and the selectors decide to make a change, Guptill will need an opening partner. Dean Brownlie, who was drafted in as Guptill's replacement, is making a decent bid. Without setting the world alight, he has been consistent with scores of 63, 31 and 34 against Australia and South Africa.

"It's hard to tick all your boxes at the same time, yesterday we certainly had more answers than questions," was Hesson's guarded response to Latham's returns. "I think we are travelling alright."

Another name touted is George Worker, the 27-year-old Central Districts batsman with two ODI and T20 caps each from 2015, who enjoyed a prolific Ford Trophy season. He was the leading scorer with 659 runs at 82.37 including a high-score of 181. He also provides some handy left-arm spin which claimed 12 wickets in the same competition, the highest for his team.

There could be a chance for fringe players to make a late impression on the selectors during the tri-series in Ireland, also involving Bangladesh, which precedes the Champions Trophy. New Zealand's IPL-bound players, which includes Guptill and Williamson from the top order, have been given permission to miss that series while their franchises remained involved.

Although Champions Trophy squads will have to be named by early May - 30 days before the tournament starts - under amended ICC regulations for global events changes can be made without ICC approval until May 25 when the ICC officially takes control of the tournament.

It would be extremely harsh on anyone named in the initial squad to then be dropped, but in such a short, sharp tournament there is little room for passengers. In reality, though, New Zealand have three more matches against South Africa to make up their minds.