Gillies made over 100 senior appearances for City in the 1950s but it was as a manager of the club that he'll truly be remembered.
His career as a player really got going with Bolton Wanderers after Gillies started his career in his homeland with Winchburgh and then Motherwell. He was on RAF service when he signed for the Trotters and played as a guest for numerous clubs including Arsenal and Chelsea during the war.
However, he went on to captain Bolton and become a key member of their team, playing in defence, in the First Division. When the war ended City quickly swooped for his services and signed him in January 1952. He made his debut the same month at home against Doncaster Rovers and never looked back.
He was a City regular and two years later was part of the club's Second Division championship team. However, he eventually lost his place in the Foxes first-team. But it wasn't the end of Gillies at Filbert Street as, after turning down offers from abroad, he became a coach at the club. In November 1958 he then moved up the ladder, becoming acting manager when Dave Halliday resigned from the position.
The Foxes were battling against relegation at the time but Gillies' appointment helped swing the tide and an improvement in results eventually saw him appointed to the role on a permanent basis. He stayed at the club for a decade and helped City to two League Cup finals at Wembley, as well as maintaining the club's position in the top flight.
He was very much part of a coaching 'team', regularly paying tribute to his coach Bert Johnson. Therefore when the club decided to sack Johnson, Gillies soon followed him by way of resignation. He went on to manage local rivals Nottingham Forest but he couldn't repeat his success at the City Ground.