Jobson was born in Hull. He began his football career playing part-time for Burton Albion in the Northern Premier League while studying for a civil engineering degree at the University of Nottingham. In 1982, he abandoned his studies when Graham Taylor signed him for First Division club Watford. He played 13 times for the Hornets in 1982–83 – their first top division season ever – and scored once as they finished second. He managed 13 league appearances again in 1983–84 – this time scoring twice – but did not make the squad for the FA Cup Final, which Watford lost 2–0 to Everton. He played twice, scoring once, in the 1984–85 season before accepting a £40,000 offer to join Third Division promotion challengers Hull City on 7 February 1985.