The four-tries-to-one win at Allianz Stadium was the side's most polished performance so far, but he's right. They can get much better.
After overplaying their hand with some audacious attack in their first three games, the Warriors found a good mix of flair and control with the ball and could have scored another couple of tries if not for lapses in execution and support play.
New recruits Adam Blair, Blake Green, Tohu Harris, Peta Hiku, Leivaha Pulu and Agnatius Paasi are naturally looking more at home with every game they play.
The rest of the side are going about their jobs well, with captain Roger Tuivasa-Sheck and hooker Issac Luke in top form, and collectively, the whole group are riding a wave of confidence and enthusiasm.
Kearney knows his players are growing in self-belief but would prefer they retain the desperation and underdog mentality that drove their efforts to improve throughout pre-season.
In a rare admission, he confirms the obvious that the side is thriving on the challenge of winning away from home, when Warriors teams of old traditionally struggled outside of Auckland.
"Absolutely," he said. "We just prepare well to play well and that's what the guys have been doing. Whether they are at home or away, we're not really fussed about that."
Rather than highlight their ability to pile on points or hold out their opposition defensively, he is most proud of his players' attitude and commitment.
"For me, it's the manner and the spirit and trust that they're playing with. I keep saying it, and I know I might sound like a boring prick, but the reality is there's another challenge in front of us next week and that's the truth."
That challenge is next Saturday's double-header at Mt Smart Stadium against the Cowboys, who have lost their last three matches but have had the wood on the Warriors for the past three seasons.
Johnson is a big chance of returning from a groin strain and prop James Gavet, who also missed the Roosters win, may overcome a hamstring problem.
Bench front rower Sam Lisone will be back after serving a one-game suspension, and veteran forward Simon Mannering is on course to return from a shoulder injury.
"[Mannering] will have to get through a full week's training but at the moment, that's what we're looking at," Kearney said.
