 After becoming a first team regular aged 17, he won a Scottish League Cup winner's medal against Rangers in 1989 and a Scottish Cup winner's medal in 1990 against Celtic in a match which ended with a thrilling penalty shoot out (9–8, Robertson scoring his kick).Robertson moved to Rangers for £970,000 in 1991.With the Ibrox club, he helped the club to the last six of their joint-record nine championship titles in a row, as well as adding three more Scottish Cups and three more League Cups to his collection.