The Olympic champions finished top of their pool at last weekend's Sydney tournament, including wins over Samoa and New Zealand.
But their title hopes were ended with a 24-7 defeat by the USA in the Cup quarter final, before the All Blacks Sevens cruised to a 31-7 victory in the playoff for fifth place.
Gareth Baber said they weren't good enough when it mattered, with kick-offs an area that needs some work.
"Some of the processes fell down for us and we questioned ourselves and as a group in terms of when the pressure comes on ensuring that you stick to a plan, you execute that plan and we didn't do that," he said.
"It's a tough environment, especially when you're not getting the results or performances you want and you've got to be brave enough as a group of players and our staff as well that you're willing to take the criticism, learn from it and move forward and that's certainly been the emphasis of this week."
Fiji play Wales and Spain first up in Hamilton this afternoon before closing out pool play against an Australian side buoyed by their victory on home soil last weekend.
The Pacific Island side prevailed when the teams last met in Dubai two months ago and Gareth Baber is backing his players to rediscover their winning touch.
"Australia have been there and thereabouts and then suddenly put in the performance of their year or the last few years to top it in Sydney in a home tournament, which is great for them."
"And we're doing something similar - we're working to plans and, as I said in fairness to (their coach) Andy and the Australian team, I think they were very good for that win in Sydney and it's going to be a tough one for us in our pool but we've played them several times over the last few years and we tended to have the drop on them so I'll be looking to do the same again this weekend," Baber said.
Samoa insist they're on the right path despite some underwhelming recent result in the World Series.
The Manu missed out on the Cup quarter finals in Sydney last weekend after being thrashed 31-5 by Fiji and 31-0 by New Zealand in pool play, while they ended the weekend with a five point loss to Wales.
But David Afamasaga, who scored his first World Series try in the win over Russia, believes they're not as far off the pace as results may suggest.
"The scoreline doesn't reflect the way we play. I think we're playing a pretty good brand of footy at the moment but just our little mistakes that we're making are letting other teams in. I think we're just there, we're nearly there but I think we're coming up," he said.
Samoa will face Kenya, the United States and Canada in pool play at the inaugural Hamilton Sevens today.
Afamasaga said they have a very good chance of making the knockout rounds this weekend if they get their "head-space" right.
"Just being very decisive, not being in two minds and once you make a decision just go for it. So that's what we've been working on."
Papua New Guinea face another daunting start against World Series champions South Africa and England in pool play.
The Pacific minnows were thrashed 50-0 by the Blitz Boks in their opening match in Sydney last weekend before a 35-5 against the English.
The Pukpuks coach Dougie Guise could be forgiven for cursing their bad luck but said it's all valuable preparation for the World Series qualifier in Hong Kong in April.
"We really want to qualify this year to get core team status (and the chance to play every tournament on the World Series)."
"We really want to push forward in winning the qualifying tournament there to get on the circuit. It's a good thing to challenge the best to try to be the best so I'm really happy that they've given us both the number one and two seeds - the World Series champions and the runners up from last year - so yeah (we're) really happy with that," Guise said.
PNG will also face Russia in their final pool game.