Johnson was playing with the amateur rugby team Blackbrook ARLFC in 2009 when he signed a deal with St Helens to play professional Super League rugby. He was put on a dual registration deal with St Helens and Whitehaven and came off the bench twice during the2010 season for Saints, featuring in wins against Huddersfield Giants and Wigan Warriors. He also made six appearances for Whitehaven.
In October 2010 it was announced that Johnson would leave St Helens to join Wakefield Trinity Wildcats on a two year deal. He made his debut for the club in the New Years’ Day Festive Trophy which Wakefield lost 22-40 to Leeds. Despite Wakefield losing the game, Johnson was named Man of The Match for his contribution to the game.
He went on to make 25 Super League appearances for Wakefield in 2011, being selected in the first 13 in all but one game. He also scored tries against Bradford and in both home and away games against Castleford and Harlequins.
Johnson was awarded both the Players’ and Coaches’ Player of The Year award at the 2011 Wakefield team awards.