Faf du Plessis stands in as captain for de Villiers, and while de Villiers has an outstanding record - averaging 50.46 in 106 tests - New Zealand have fared well against him. He averages 'only' 39 in 10 tests against New Zealand.
By contrast, Steyn, whose battles with groin and shoulder injuries have sidelined him for six of South Africa's last eight tests, has a terrific record against New Zealand.
In 10 tests, he's taken 58 wickets, at 17 apiece. Last time out, three years ago, the hard-nosed quick took 13 wickets in two tests at an astonishing rate of 11 runs each.
Overall his 406 wickets in 82 tests have cost him 22.53 each, statistics which illustrate his standing among the elite of the modern fast bowling exponents.
As for Philander, hindered of late by ankle ligament damage, his return in four tests against New Zealand is 28 wickets at 14 each; 126 at 22 overall in 32 tests.
So in one sense New Zealand have caught a break, but their batsmen have discovered their job just got considerably harder.
"It is most unfortunate that we will not be able to call on two players of the quality and experience of de Villiers and Morkel," convener of selectors Linda Zondi said. "However, we are fortunate to have a capable stand-in captain. With both Dale Steyn and Vernon Philander fit and firing again I am confident we have the players to take on New Zealand."
The series will be South Africa's first since a memorandum of understanding was signed with the South African Government.
It introduces a target on the number of black and coloured players in their teams.
Specific numbers have not been confirmed.
However, Afrikaans-language newspaper Rapport claimed CSA have agreed on six players of colour in every starting XI, of which at least two must be black. In this squad, South Africa have seven players of colour, including two black Africans.
South Africa's squad of 15 has only had A class matches to prepare in the last seven months since facing England.
Fast bowlers Kyle Abbott and Kagiso Rabada has played some county cricket; the rest have been occupied in T20 leagues.
South African squad: Faf du Plessis (c), Hashim Amla, Stephen Cook, Dean Elgar, JP Duminy, Temba Bavuma, Stiaan van Zyl, Quinton de Kock, Chris Morris, Wayne Parnell, Kyle Abbott, Vernon Philander, Dale Steyn, Dane Piedt, Kagaiso Rabada.