The visitors look set to welcome back Ben Stokes – who has played six matches for Canterbury this season - for the first time since he was charged with affray after a scrap outside a Bristol nightclub in September.
Stokes has pleaded not guilty and the case has been sent to the Bristol Crown Court. The first hearing is scheduled for March 12. Stokes is not be required to attend.
If the ECB had prevented him playing this series, they risked a lawsuit for breaching restraint of trade laws.
England captain Eoin Morgan said despite the distractions, Stokes was ready to return provided he does not stiffen up after training.
"It's the skill of any professional sportsperson when it comes to doing your job.
"[Playing] can be a nice release because you get to focus on one thing rather than wider things that are going on.
"He looks in great nick, and he's hit the ground running since he's been involved."
No decision had been made on who Stokes might replace. Batsman Alex Hales looks vulnerable if they maintain six bowling options.
Stokes can now get on with bashing balls and attacking batsmen on a Seddon Park pitch expected to favour spin.
"It's a used surface and was on the slower side [against England in the T20]," New Zealand captain Kane Williamson said.
That will have the Black Caps pausing to consider their personnel.
Mitchell Santner's bowling record in 50-over cricket remains strong, and Todd Astle has made a sound start in six ODI outings, taking seven wickets at average of 21.42, economy rate of 5.35 and strike rate of 24. Santner (knee) and Astle (side) are recovering from minor strains.
The recalled Ish Sodhi could slot in, too. He looked tidy in his T20 outing against England in Hamilton, taking one for 31 from four overs.
There's no room to play all three, provided Colin de Grandhomme and Henry Nicholls retain their places. Another point to consider is the stock ball of each going into left-handers, of which England's top seven could have three.
As a result, Williamson's off-spinners might be used to take the ball away. He took two for 32 from 10 overs at Hamilton against Pakistan in his only appearance at the ODI bowling crease this summer. One over bowled to England's T20 side at the same venue cost 16.
Morgan hinted leg spinner Adil Rashid and off spinner Ali will play.
"It has the potential [to spin]. We found that after batting first [in the T20]. On the same wicket and with similar conditions it took a lot of spin and dewed up in the evening."
Williamson was convinced they need to park - but not forget - their T20 focus.
"[The format] keeps pushing the boundaries of cricket whether into the one-day or test game where people are more positive.
"It doesn't completely change it, but [in ODIs] you come up against situations where more defence and batsmanship are required.
"[T20's] having an influence, but it's important not to get carried away when the conditions might dictate something else."
FACTBOX
• England have come off a 4-1 series victory over Australia as they firm as World Cup contenders at home next year.
• Ben Stokes returns to the England squad for the first time since he was charged with affray after a scrap outside a Bristol nightclub in September.
• New Zealand come into the series on the back of eight straight ODI victories, but they have lost six of their last seven T20s - against Pakistan, Australia and England.
• Ish Sodhi returns to the New Zealand squad and could play his first ODI since May. Todd Astle, Lockie Ferguson, Matt Henry, Tom Latham and Henry Nicholls also switch back in for the 50-over format.
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