The 26-year-old is something of a late bloomer having spent the majority of his early career in non-league football before arriving at the Kassam Stadium via 18 months with Motherwell in the Scottish Premiership.
And Johnson looks almost certain to maintain his recent rise with a switch to the Championship beckoning in the summer.
The Birmingham Mail reports that his electric performances, plus five goals from out wide, have caught the attention of a number of clubs higher up the footballing ladder with Wolves and QPR reportedly in the mix.
Wolves boss Paul Lambert added both Andi Weimann and Ben Marshall to his squad in January but with the Midlanders hovering just above the relegation zone, the Scotsman could be forgiven for wanting to add some fresh blood to his squad.
And the same could be said for Ian Holloway at QPR. The capital club have flattered to deceive at times this season while their goal tally is among the poorest in the division.