Born in Lambhill, Glasgow, McPhail attended St Mungo's Academy before signing for Celtic, the club he supported, in October 1941 from junior side Strathclyde, aged just 17.
In 1945 he did earn a winner's medal in the minor Victory In Europe Cup, but in 1948 was part of the Celtic team that only narrowly avoided relegation on the last day of the season.
Journalist Archie Macpherson recounts that McPhail admitted to him that he began to adopt the "ageing remedy of the Hungarian international Ferenc Puskás, shortening the stride and increasing the number of steps he took to lend the false impression of pace.
[4] His younger brother Billy McPhail also played for Celtic (joining the club at almost the same point as John retired), and is widely remembered for scoring a hat-trick in their 7–1 victory over rivals Rangers in the 1957 Scottish League Cup Final.
[8] John McPhail had also scored three goals against Rangers, in the 1950 Glasgow Merchants Charity Cup final;[9] this is the only occasion in Old Firm history that brothers have achieved this feat.