"You never want to focus on individuals too much, but for me it's an awesome challenge.
"I'm going to try to put my best foot forward against a teammate and a former teammate, so I'm looking forward to it."
Johnson said he'd have no problems dishing the dirt on the pair if it would help the Kiwis coaching brains trust to identify any potential frailties in the Tongan line-up.
Kiwis coach David Kidwell is being assisted throughout the tournament by former NRL veteran coach Brian Smith and North Sydney Bears Intrust Super Premiership coach Ben Gardiner.
"We've got some extremely good coaches that I'm sure will pick out some areas that we want to try to exploit, in their games, in their forward pack, and right across the park," he said.
"If there's something there that I can see on either Tui or Ata, then I'll speak up.
"But it's not an individual or a personal thing. It's for the benefit of the team and if there's something that I can put forward then I will."
It goes both ways however, and Johnson is not fazed by talk the Tongan defenders will have their sights set firmly on his No7 jersey.
The 23-test veteran is used to be singled out for special treatment at club and international level and expects more of the same tomorrow.
"Everyone always says that they're going to target me.
"We're going to target people in their team as well so it doesn't really matter.
"That's the way the game goes and you always want to play in these big physical games and I'm looking forward to it."