A former non-league player with Harrowgate Railway Athletic and then Harrogate Town, Jon was handed his chance in professional football with Bradford City in 2008.
He made his debut in May 2009 against Chesterfield while his breakthrough came during the 2010/11 League Two campaign in which he made 25 appearances.
In May 2013 he was a member of the side that beat Northampton Town in the Play-Off final at Wembley and he spent a season in League One before joining Burton Albion ahead of the 2014/15 season.
In three seasons at the Pirelli Stadium he enjoyed great success, with the Brewers winning the League Two title in 2014/15, then clinching promotion to the Championship the following campaign.
Jon was then a regular in the Championship as Nigel Clough’s side maintained their second-tier status before joining Scottish Premiership side Hearts in August 2017.
While he was a regular, he spent just one season in Scotland before joining Sunderland and he has been a regular in his two seasons at the Stadium of Light.
Edinburgh-born, he was called up to the Scotland squad for the first time in March 2018 and went on to make his debut against Mexico that June.