[6] On 9 August 2019, MacKay and goalkeeper Daniel Hoban were loaned by Inverness to League Two club Elgin City.
[7] On 29 July 2021, MacKay scored his first goal for Hibernian in a competitive game against FC Santa Coloma in a 2–1 win in the UEFA Conference League qualifiers second-leg.
[13] In 2017, MacKay played for the Scotland Schoolboys team, along with fellow Inverness Caledonian Thistle team-mate, Kieran Chalmers.
He scored in a match against England a day before he featured in the 2018 Scottish Challenge Cup Final, where he provided the assist to the winning goal from Carl Tremarco.
[14] MacKay featured prominently in the second game, missing three good chances but winning a penalty kick that led to the match-winning goal.