 He subsequently joined Barnsley.Having arrived at Barnsley on a short term deal, Letheren then signed a new deal to keep him at Oakwell until 2008 Two years after joining the club, he made his debut in the 3rd round of the FA Cup against Blackpool on 5 January 2008, as a half-time substitute, replacing the injured Heinz Müller.At 1–0 down 'the Tykes' went on to win the game 2–1, giving Letheren his first clean sheet on his debut.