King joined Rovers initially on loan from Manchester United and impressive displays meant it was quickly converted into a permanent deal with the Norwegian international signing a two-and-a-half year deal in January 2013.
Oslo-born, the attacker started his footballing career with Valerenga before being scouted by Manchester United, signing for the Premier League club in January 2008 as a 16-year-old.
King quickly progressed through United's Academy and then onto their Reserve-team before securing a loan move to Preston North End in 2010.
The following year was spent earning experience with Bundesliga side Borussia Moenchengladbach, whilst last year the striker was on loan at Hull City.
Able to play through the middle or out wide, King has honours at all levels with Norway.