Sportal.co.nz 02.Feb.2013Getty Images
The All Blacks Sevens booked a clash against pool D winners Australia after losing to England and grinding out wins against Spain and the United States on day one at Westpac Stadium.
The New Zealanders - HSBC Sevens World Series leaders heading into their home tournament - played well below their usual standards and paid the price, finishing runners-up to England in pool A.
Australia went through day one unbeaten and looked impressive, especially against Fiji, who failed to make the Cup quarter-finals for the first time in their history.
"If we play like we did today we certainly haven't got a show tomorrow against Australia who are playing pretty well," said a disappointed Tietjens.
"But putting a finger on it, perhaps it's because a lot of them haven't played sevens for a while. The younger guys seem to be coming on with a bit more energy and wanting to give it all.
"But it's the mistakes that are costing us in crucial areas at certain times too which is worrying."
Given Fiji's downfall and the fact that South Africa scrapped into the Cup section by the skin of their teeth, after losing to Samoa and Canada, New Zealand at least won't lose ground as far as the overall series is concerned.
"I think in some ways we're lucky we're still in the Cup," said the highly-respected coach.
"When you saw the second [France] and third [Fiji] team in the world series are in the bowl. From a points differential getting a few more points it probably helps by staying in the Cup.
"I know the guys will come out. We've got to play 100% better than what we played today. I'm sure they'll pick it up.
"They are a pretty quiet bunch in there at the moment. They are not happy. They set high standards. We haven't met those standards and it's the core group that are very, very unhappy. We've got to put it behind us. Day two is another day."
Taranaki fullback Kurt Baker is not expected to feature on Saturday after suffering a hamstring strain in the final match against the USA.
And Tietjens has not ruled out giving young guns Rocky Khan, Belgium Tuatagaloa, Luke Masirewa and Gillies Kaka more game time if senior players DJ Forbes, Lote Raikabula and Tim Mikkelson don't start firing.
"Some guys will be worried about their position I suppose it's fair to say," said Tietjens.
"They are not playing as well as they'd like. I've got to weigh that up on a larger scale and look at the match we're playing and where we're playing with the support that we have.
"I know some of those players can perform when it's really needed. They are going to have to do that tomorrow."