Yet Williamson remains upbeat, is sure there will be enough time in the next five days for a decent amount of cricket to be played, and has faith in his young players to grab a chance.
"We've got an exciting young side. The guys are raring to go and looking forward to the challenge," Williamson said at Seddon Park in Hamilton yesterday, his mind partly still on that second test tumble at the Basin Reserve in Wellington last weekend.
"It's very important we bounce back, show that fight and those characteristics that this team is about and which we failed to do in the latter half of the last game."
Without being silly about it, the first thing is New Zealand have to figure out how to get 20 wickets.
It's the standard test riddle but on this occasion they'll know there won't be any favours coming from South Africa.
So they need a team with a wide range of bowlers to cover all eventualities.
That might mean a lengthening of the tail.
Sometimes you have to take a punt.
A couple of small slips of the tongue yesterday hinted that allrounder Colin de Grandhomme, whose bowling has far outweighed his batting contributions, will play, alongside Matt Henry, the experienced Canterbury seamer.
But whether there's room for Trent Boult's replacement in the squad, the lively but uncapped Scott Kuggeleijn, will have to wait until this morning.
If South Africa's skipper Faf du Plessis is right, the Seddon Park pitch will be turning well before the end.
If so, Mitchell Santner could return to give New Zealand four frontline bowlers, two seam, two spin plus de Grandhomme.
Du Plessis has some sympathy for Williamson's plight, both for his own situation but also losing two key bowlers before a vital match.
"If we lose guys like them in our side it will be a huge loss," he said.
"Seeing as they've got the experience and numbers behind them, you don't just replace that in test cricket, so it's a massive hole that they will leave."
Du Plessis also gave Williamson a pat on the back, as the New Zealand batting champion has been feeling some heat after the Basin bungle.
"I think it's unfair. I think he's done really well with the New Zealand team," du Plessis said.
"He's a fantastic player. I've read a lot of times that he's the best No3 in the world.
"It comes with not winning. It's part of our job as captain and sometimes it's not nice, sometimes you feel it's not deserved."
South Africa's injured wicket-keeper Quinton de Kock seems likely to grit his teeth and play today despite a painful right index finger injury.
NZ v South Africa
Third test, Seddon Park, starting 11am today
New Zealand: (from) Kane Williamson (c), Tom Latham, Jeet Raval, Neil Broom, Henry Nicholls, Jimmy Neesham, BJ Watling, Mitch Santner, Colin de Grandhomme, Jeetan Patel, Scott Kuggeleijn, Neil Wagner, Matt Henry.
South Africa: (from) Faf du Plessis (c), Dean Elgar, Stephen Cook, Hashim Amla, JP Duminy, Temba Bavuma, Quinton de Kock/Heinrich Klaasen, Vernon Philander, Keshav Maharaj, Dane Piedt, Kagiso Rabada, Morne Morkel.
