Newcastle face the Roosters for the 2026 title on Sunday at 7:30 pm.
Underdog Newcastle may rely on Sharpe, whom Johns sees as the spark to bring the Provan-Summons trophy to the Hunter.
Johns urged him after a subdued preliminary final:
"Yesterday he played a more controlled game.
He focused on his kicking and passed the ball.
I would urge him in this game to just roam the field, pop up and drive them crazy."
Cooper Cronk agreed:
"He needs to have 15 runs."
"He needs to have a lot of runs because if he runs 15, he'll break 10 tackles.
I don't care where he runs it - dummy half, near the line, two passes wide - just run."
Against Penrith, Sharpe made seven runs for 31 metres; halves partner Sandon Smith scored twice.
Sharpe's acceleration and agility have made him a dangerous attacker and prompted discussion of Australian Kangaroos selection.