[2][b] He joined local Scottish League Division One club Ayr United from 1917 but only played once in his first three seasons before becoming a regular in the side from 1920,[9] with his absence likely related to the First World War, in which he served in Constantinople.
According to the Derby Daily Telegraph, he "has the build and weight for the position, and he adds to a nice turn of speed and dash a cleverness in ball distribution which enables him to keep both his wings going.
[3] His performances earned him a transfer to the ambitious Portsmouth club, where the local newspaper, the Evening News, suggested he was chosen because he played in "what is now known to be 'the Pompey style': constructive, unselfish, thoughtful, determined, and – when necessary – forceful", and "should do well in the more congenial surroundings at Fratton Park with real football, rather than the tearaway and haphazard conditions in vogue at Darlington".
[5] On the opening day of the season, "the best goal of the match came when McKenzie, obtaining twenty-five yards out, side-stepped an opponent, and shot, at a tremendous pace, into the corner of the net" to complete a 3–1 win against local rivals Southampton.
[1] McKenzie returned to Scotland and joined Hamilton Academical;[1][8][9] he played ten Division One matches in the first half of the 1927–28 season and scored once, a penalty in a 6–3 defeat of Dunfermline Athletic.