 After appearing frequently for Watford's first team during the 2008 pre-season, he made his competitive debut on 12 August 2008 whilst still an academy scholar.Jenkins played the entire game as Watford beat League One side Bristol Rovers 1–0 in the League Cup.He remained in the club's League Cup team, playing full games against Darlington, West Ham United and Swansea City before Watford bowed out to Tottenham Hotspur in the quarter-final.