Career
Born in Merthyr Tydfil, John progressed through the academy at Cardiff City. His professional debut for Cardiff came on 14 August 2012, in a 2–1 home defeat to Northampton Town in the first round of the Football League Cup. John made his league debut on 17 August 2013 in a 2–0 loss at West Ham United, Cardiff"s first game in the Premier League.
He made 20 appearances that season, appearing more frequently in the second half of the campaign, as the Bluebirds were relegated.
On 6 March 2015, John was loaned to Barnsley on League One for the remainder of the campaign. On 17 February 2016, he was loaned to Chesterfield for an initial month.
He was an unused substitute in both games. The following month, he retained his place in the squad for the qualifiers against Macedonia and Belgium.