Ranger joined the Magpies in 2009 following spells with Crystal Palace and Southampton, with his career at the latter club littered with disciplinary problems.
The former England Under-19 international made his Newcastle debut against West Brom in 2009 while the club were playing in the Championship and went on to make 62 appearances for the club, scoring just two goals.
Throughout his short career so far, the striker has endured a number of problems relating to football and his everyday life.
While at Southampton he spent 11 weeks in a young offender's institute for robbery, but more recently in 2011 and 2012 he was charged for being drunk and disorderly, and was released on bail after being arrested on suspicion of rape in late January.
Ranger's last outing for Alan Pardew's side was during the 2-0 FA Cup defeat to Brighton & Hove Albion on January 5 2013.