Shields began his professional career with Raith Rovers in 1998 and his early form earned him a spell training with Tottenham Hotspur the following year.
At the start of the following season, Shields undertook his third loan spell, this time with Queen of the South[6] and when he returned to Celtic Park in January 2003, he was promptly released, joining Clyde on a short-term deal.
[10] In the first half of 2005, Forfar rejected approaches from Stranraer[11] and Grimsby Town,[12] although Gillingham secured his signature in a £25,000 deal.
[14] In August 2007, Shields was released from Livi on his 26th birthday, allowing him to move with fellow player Daryl Smylie to Swedish side Östersunds FK.
[15] Shields took a year out of the game after his spell in Sweden, before joining Junior side Bo'ness United in August 2009.