[2][3] Duffy played for the Leigh Centurions, Salford City Reds and Warrington Wolves in the Super League, and also for Whitehaven.

He has held the position of head coach at the Swinton Lions and Featherstone Rovers in the Championship.

Duffy was born in Platt Bridge, Wigan, Greater Manchester, England.

Duffy became Super League's youngest débutant when he made his Warrington Wolves début at the age of 16.

He immediately took up a new post with Featherstone Rovers after their coach Jon Sharp left the club.