 Jenkins made his league debut in the defeat at Barnsley on 15 November 2008 under the management of Malky Mackay, and retained his place in the team thereafter, scoring his first league goal in the 3–2 defeat at promotion contenders Birmingham City on 6 December.In 2009, Jenkins formed a midfield partnership with Jack Cork under manager Brendan Rodgers in which the team climbed to 13th place in the league by the end of the season.He made his 50th start for Watford on 20 October 2009 against Ipswich Town.