After being touted as a prospect to watch since signing from Barrow as a schoolboy, Harrison made 16 Super League appearances in his debut season in 2007, settling into the first-grade arena and hinting at possible higher honours. At the end of the season he was rated 13th best teenager in world rugby and 5th best in the UK according to Rugby League World magazine, and penned a three-year contract extension. A well-built loose forward with good hands, he fast-tracked his A-level studies a year early to free him time to train with the Wolves first team as a sixth former. Hailing from Cumbria, he was scouted by Wolves assistant coach Gary Chambers while playing for Barrow Island, and has a fine junior representative career. Played for Cumbria from U12 to U16, Lancashire at U17 and U18 levels and featured in the England side from U15 to U17, captaining England Schools at U16 and facing the Australian Institute of Sport at the end of 2005. He had a fine series for England Academy against Australia Schoolboys in 2006.