Born in Manchester, Berkeley began his career with Gretna. He spent nine games on loan at Conference North side Workington in 2006. He made his debut for Workington on 4 February 2006. He scored his first goals of the loan period, netting a hat-trick against Northwich Victoria at Borough Park on 18 February. It was announced before Workington's trip to Northwich on 23 March that he would return to Gretna to help their Scottish Cup campaign. He finished his loan spell by scoring the opening goal of the game, although Workington eventually lost 4–1. He was released by Gretna in 2007.