Johnson spoke openly last week about how criticism both of his early season form and his place in the Kiwis squad, together with a desire to repay his supporters, had motivated him to turn in a five-star performance in the Anzac test.
He produced the goods again for the Warriors when it mattered most against the Sharks but his game was far from complete and two moments of brilliance overshadowed some wayward kicking and passing and ineffective last-tackle plays.
But Johnson's search for that 80-minute consistency at club level is made difficult as he juggles the two roles of being the Warriors' chief organiser and playmaker.
He is spared that burden in the national set-up when paired with a leader like Kieran Foran and surrounded by the highly efficient and accurate Kiwis.
McFadden is conscious of the weight of expectations on Johnson's shoulders and of the 24-year-old's sensitivity to recent criticism.
McFadden conceded his side had been down on confidence and described Johnson's performance as "solid" but, despite his match-winning contribution, improved game management and better execution will be needed from both he and five-eighth Chad Townsend in the weeks ahead.
Otherwise, the Warriors did well to follow through on pre-match talk about improving their line defence.
There were some courageous efforts - Tui Lolohea's second try-saving tackle in two games perhaps chief among them - and they showed resolve to survive periods of sustained pressure.
Pedantic refereeing impacted heavily on the match and some basic errors - notably Kata's no-try fumble and Dominique Peyroux's sloppy play of the ball - continued to blight their play.
With four wins from nine starts they now sit back up in eighth spot on a heavily congested NRL ladder.
Finding consistency and retaining their place with the top half of teams is now key as even last-placed Manly remain just two points apart from the sixth-placed Roosters.
With Manu Vatuvei expected to spend time on the sidelines with a sternum injury and Konrad Hurrell likely to join him through suspension, after his raised knee sent Anthony Tupou to hospital with a broken jaw, both sides of the Warriors attack are facing changes.