"Shaun can be the best player in the world and he's just got to find consistency. If he can do that week-in, week-out and he can drive the team and get the best out of the players around him they would make the top eight every year. But the responsibility is on Shaun."
Johns acknowledged that the 24-year-old Kiwi had improved and developed his game over the past 12 months, but says he still has a tendency to go missing at key stages.
For Johnson to fulfil his potential, Johns says he must show a greater ability to control a game, particularly in the final quarter when the result is hanging in the balance.
"I do see progression in his game. I see him do things which no one else can do but then I see him have quiet games. He's still only very young and he's still learning his trade," he says.
"You look at Johnathan Thurston and you look at what Darren Lockyer used to do, they own the game. Especially that last 15 minutes and that's what Shaun has to do.
"I'd say he knows that and Andrew McFadden knows that. It's all about the learning curve for Shaun."
After a glittering career in which he played 249 games for the Knights, 23 State of Origin matches for New South Wales, and 24 tests for Australia, Johns is widely accepted as the leading authority on the modern game.
The two-time Golden Boot winner and three-time Daly M medallist is frustrated with the generic and overly structured style of play that has crept into the NRL in recent years but believes the game is in another transitional phase.
"I think it's about to go back to a more ad-lib style. The last three years it's been really frustrating watching how structured a lot of the plays are. The over-reliance on the set play has been stifling halfbacks. Some teams have become like American football where they just work to one point of the field and they have the same play."
Johns longs for a return of the wide-sweeping backline plays employed by the likes of the old Canberra and Brisbane sides of the early to mid-90s and says the long cut-out pass is under- used in the modern era.
"We're in another transition around the way the game is being played and I think that sort of stuff is coming back into the game. All that second man play can be effective but I think teams have worked that out and are going away from that now. Everything old is new again and gets reinvented, so I think teams will definitely look at that sort of play."
With defensive lines so well-drilled and quickly up in the face of attacking teams, Johns says a simplified game plan can provide the time and space for more expansive football. The Warriors are well suited to such patterns but he concedes getting the balance right is difficult.
"Definitely [it can be achieved]. Just through power running and offloads and playing off the cuff. But it's a fine line and if you go over it and go too expansive you can get errors. But that's when the Warriors are at their best, when they can find that fine line where they can play that ad-lib football where they get in offload mode there is no way to defend it. When they're playing that style they are so enigmatic because it can work or it can be horrible. When it works they can blow teams away; they've just got to find that fine line."
