The central defender was included in Rovers` first-team squad for the first time for the match against Accrington Stanley in September 2015 when he was an unused substitute.
He was allocated squad number 32 and given a first-team contract in the summer of 2016, the only scholar to be upgraded to the pro ranks.
Kilgour spent time out on loan with Evo-Stik League South West sides Cirencester Town and Mangotsfield United last season.