On 18 August 2006, Mannone was sent out on a three-month loan to Championship club Barnsley, where he was expected to challenge Nick Colgan for the number-one spot. He made his debut in the League Cup against Blackpool on 22 August 2006. After a 2–2 draw, the game went to a penalty shootout in which Mannone saved a penalty from Keigan Parker to help his team through to the next round. However Mannone's time at Barnsley was ultimately not a happy one. Making his league debut in an away game to Preston North End on 22 September, he came on as a substitute after Colgan was sent off. He punched a cross onto Patrick Agyemang's head and the ball bounced in for the winning goal to Preston. In his next match, starting in place of the suspended Colgan, against Luton Town, he dropped a cross late on and Ahmet Brković scored the winner.