"I would be surprised [if Harris played at five-eighth]," Australia coach Tim Sheens said before pointing out that the time available meant he was more worried about his side than anything the Kiwis might throw up.
Team namings don't always mean much in rugby league. NRL clubs regularly change their side from the one named on a Tuesday and Kearney has every opportunity to tinker with things almost up to kickoff.
He is in this predicament because of injuries to Kieran Foran, Thomas Leuluai and Josh Hoffman and non-selection of Sonny Bill Williams which has exposed a lack of depth in playmaking areas.
John is obviously more accustomed to playing five-eighth but has seen little first-grade action with Penrith this season and, like halfback Shaun Johnson, is defensively vulnerable.
Harris offers more defensive security, which might appeal more to the naturally conservative Kearney, and it was the original plan.
Both are in the playing 17 - at this stage - and could spend time there.
"Wouldn't you like to know," Johnson said when quizzed about the identity of his halves partner, clearly enjoying the mystery.
The Warriors halfback is under the impression he will play on both sides of the ruck, which lends weight to the Harris argument. He will also be charged with virtually all of the kicking duties, which means he will attract plenty of attention from the Kangaroos.
"I have never played on the ball as much before when it's been right or left edge," he said. "It's not what I'm used to but I see it as an opportunity to keep me more in the game. When you have that onus on you, you really have to deliver. You have to play for 80 minutes because that's what the boys expect. I'm excited about it.
"I have always had backup with Foz [Foran] or Benji [Marshall] running the show. To be that front man, it refreshes me a bit and gives me an opportunity to do something I'm not really used to. In terms of my development and growing as a player, it's a pretty big step."
At least he's playing in a familiar position.
On top of the five-eighth conundrum, Ben Henry, a second-rower or centre, will start at hooker.
"Our job is to make sure we're on-song and don't drop our intensity and don't take it for granted that everybody's saying we're an unbackable favourite," Sheens said.