born in luton, england to a galway mother and a dublin father, greene played for the republic of ireland u21 side 14 times. he began his career at hometown club luton town, where he spent five years, making just 19 league appearances. then manager david pleat's move from kenilworth road to take over at sheffield wednesday brought greene into immediate conflict with the new luton manager, terry westley. greene was loaned out twice during his time with luton, firstly to colchester united and then to brentford. he was sold to colchester for £30,000 in 1996, and went on to make over 150 league appearances, being named player of the year in two consecutive years. greene moved on to play for cardiff city in 2000, making 10 league appearances, and made a solitary league appearance for cambridge united in 2001 before retiring through injury.