Gary’s football career began at Mangotsfield United in the Southern League and in the summer transfer window of 2006 he went on trial at Bristol Rovers with a view to permanent contract, but he eventually opted to join Team Bath.
In July 2009, following the disbandment of Team Bath, Gary signed for Newport County, and was appointed captain. In the 2009-10 season, Newport County were crowned Conference South champions with a record 103 points, 28 points ahead of second-placed Dover Athletic. On 12 May 2012, Gary played his final game for Newport in the FA Trophy at Wembley before moving on to Inverness, where he captained the side and made 218 appearances. He enjoyed much success seeing the club win The Scottish Cup and playing in Europe for the first time. He is a commanding player, leading by example at all times.
After six years in Scotland with Inverness Caledonian Thistle, Warren heads south of the border to relocate closer to his Bristol roots, signing a 2-year deal with Yeovil Town.
After a successful loan spell, Gary signed with Torquay in 2020.