Their understanding seems instinctive, but has developed from time training and playing together, as they came through the grades at the Warriors, before Hiku left for Manly at the end of the 2012 season.
"We played a lot of junior football and we played [under] 20s together," said Fusitu'a. "So right from the start of this season we already that connection. We knew each other well. It meant we were always on the same page, right from the beginning."
That was evident in Fusitu'a's blistering start to 2018, as he scored 11 tries in the first nine games, including doubles against the Rabbitohs, Raiders, Cowboys and Storm.
Hiku is an old fashioned footballer, with a knack for the unexpected.
He draws in defenders with his footwork and sleight of hand, but is always looking to release his winger.
"He's a great player," said Fusitu'a. "He's got a lot of experience behind him; he's already played 100 games but he is still young (25). He's got a lot of flair and we all have things we have to work on as players. It's definitely good to be on the outside of him, getting those good offloads."
The depth of the Warriors this year is summed up by Gerard Beale, who won a premiership with the Sharks in 2016, being on the bench.
Beale impressed with his solidity and anticipation in defence during his recent first grade spell, before being injured in the round 23 loss to the Bulldogs.
Hiku was recalled, and has performed superbly since.
Despite some defensive occasional defensive issues, there seems to be a sharper edge to the Warriors attack when Hiku is on the team, which will have persuaded Kearney to stick with the status quo.
"We have built into a good combination this year and hopefully we can take it to the next level this week," said Fusitu'a. "But our preparation needs to be on point."
The Warriors completed their final training session at Mt Smart on Wednesday, again accompanied by loud music, to simulate the potential atmosphere on Saturday at ANZ Stadium.
Simon Mannering is making encouraging progress and took some part in the session, though stayed away from the contact work.
Captain Roger Tuivasa-Sheck did some work in the gym then watched the training from the sideline, still protecting his sprained left ankle in a brace.
The Warriors depart for Sydney on Thursday afternoon.