Jardine signed for Rangers in 1964. Signed as a midfielder, he spent a couple of years in the reserves before making his debut aged 18 in a 5–1 league win at home to Hearts on 4 February 1967, playing at right-half. This match took place a week after Rangers had been knocked out of the Scottish Cup by Berwick Rangers. He scored his first Rangers goal a few weeks later on 18 March 1967 in a league match against Ayr United. That same season Jardine played in the 1967 European Cup Winners' Cup Final against Bayern Munich, losing 1–0 after extra time.