Two years ago the midfielder was playing part-time junior football with Clydebank on top of his day job working as a labourer.
At almost 26 years old there was a feeling that his chances of making it as a professional may have passed him by. Hamilton Academical, however, saw it differently, giving MacKinnon a belated opportunity in full-time football. Should Hamilton go on to win promotion this season, he could be playing in the SPFL Premiership next year, something unimaginable not so long ago.
"When I joined Clydebank everyone was telling me that I had a chance to turn pro but nothing happened," he recalled. "Paul Hartley spoke to me about signing for Alloa but the travelling was too much for a part-time contract.
"Then Hamilton called and I was delighted to come here. Coming into the senior game later than most makes me appreciate it more, I think. I actually enjoyed labouring but in the cold weather your hands would be freezing. So coming in for training every morning feels like a luxury."
With just 12 matches remaining, Hamilton, who take on Livingston at home this evening, are in a strong position to push for the title. MacKinnon hopes to be involved in all of those games but only if he can keep his temper under control. "I need to understand referees are not going to change their minds because I'm screaming in their faces," he said.
It has taken time for Livingston to have something to positive to shout about at all, a 3-0 win over Alloa on Saturday bringing an end to a run of five matches which comprised just one win. It was also their first victory since Stefan Scougall and Coll Donaldson were sold to Sheffield United and Queens Park Rangers respectively, departures which have caused Livingston to alter their style.
"We are having to do different things to win," said John McGlynn, the Livingston manager. "We lost Stefan and lost Coll but we still have to win matches."