The 25-year-old signed for the Scottish Championship club in September following his release from Dundee United, making 12 appearances for the club.
Gavin began his professional career at Blackburn Rovers, where he was described as one of the clubs most promising prospects in the academy, signing a two year contract with the club. During his time at Rovers, he enjoyed loan spells at Tranmere Rovers, Rotherham United, Bury and Motherwell. In 2011, Gunning made the move to Dundee United, where the defender spent 3 seasons making 99 appearances and scoring 10 goals along the way. He was also selected in the PFA Scotland Team of the Year in the 2011-12 season.
The defender then made the move back south of the boarder, signing for Birmingham City in 2014. His career at the club was cut short due to a knee injury picked up in August, which kept him out of the squad for the remainder of the season. Following a season at Oldham Athletic, Gunning made the move back to Scotland, where re-signed for Dundee United in the 15-16 season. During this period, he made 20 appearances for the Scottish Premiership club before making the move to Greenock Morton at the beginning of this season.
Gunning has represented the Republic of Ireland at Under 19 and Under 21 level, making his debut for the latter in their UEFA European Under-21 Championship Qualifier against Georgia.