He was spotted by a scout from Glasgow Celtic while the club was on tour in North America and he was signed by the Scottish club in 1951 after being invited over for a trial. Becoming the first black player for Celtic, and one of the first to play professionally in Scotland, Heron went on to score on his debut on 18 August 1951 in a League Cup tie against Morton that Celtic won 2–0. Heron only played five first-team matches in all, scoring twice. He was released by the club the next year after making one appearance in the Scottish Football League (having been unable to displace the established John McPhail) and joined Third Lanark where he played in seven League Cup matches, scoring five goals but did not appear in the League.