Owen Coyle’s ninth summer signing of 2013, the central defender began his career 15 miles from his birth place of Stevenage with Luton Town.
Barnett made his professional debut as a substitute in a Football League Trophy game against Woking in October 2002, a month before his 17th birthday.
Before breaking into the first team on a regular basis in 2005/06, Barnett played alongside Latics’ defender Emmerson Boyce in a 2003 FA Cup tie against Thurrock.
Barnett won Luton’s Player of the Season award during the 2006/07 campaign before being snapped up by promotion chasing West Bromwich Albion.
Promotion is just what he achieved in 2007/08 as the Baggies won the Championship but he only made 11 appearances the following season in the Premier League.
Following West Brom’s relegation from the top flight Barnett joined Coventry City on loan for the 2009/10 season and the following campaign saw him loaned out again, this time to Norwich City.
Another promotion was on the cards for the defender as Norwich finished runners-up in the Championship and opted to sign him on a permanent basis.
His first game as a permanent Norwich player was against Latics at the DW Stadium in the opening game of the 2011/12 season.
Towards the end of the 2012/13 season Barnett was once again involved in a promotion to the Premier League when he joined Cardiff City on loan, playing eight times, helping with four clean sheets and he was on the losing side just once.