 A product of the Manchester United youth academy, Cathcart spent time on loan at Belgian club Royal Antwerp, and English Football League Championship sides Plymouth Argyle and Watford, before joining newly promoted Blackpool in 2010.Cathcart returned to Watford in July 2014 on a permanent deal.Born in Belfast, Cathcart was spotted playing football for Glengormley High School at the age of 14, and, despite being coveted by clubs like Arsenal, Chelsea and Rangers upon winning the Northern Ireland Youth Player of the Year award in 2003, he began training at the Manchester United School of Excellence in Belfast.