 Born in Pontefract, West Yorkshire, Green started his professional career as a trainee with Sheffield Wednesday but was released at the age of 16.Upon his release he joined Doncaster Rovers, and progressed through the youth ranks to the first team, making his debut at 19 in a 2–2 draw with Northwich Victoria in the Conference on 19 March 2002.His first career goal came three days later in a 5–2 home win against Hayes (who have since merged with Yeading).