Come Saturday night, the former electrician became a livewire local rugby hero when he crashed over the line to score the game-sealing try in the ACT Brumbies' 32-15 victory against the Western Force.
"I hung up the tools this pre-season when I came in full-time. But I still do a cash job here, and now, I've even got one tomorrow," explained Mickelson.
"But I think I'm going to can that."
The hooker came off the bench in the 73rd minute on Saturday night and was met with a chorus of cheers around GIO Stadium.
Many of his local junior clubmates from the Uni Norths Owls had ditched their previously scheduled event to attend, and minutes after coming on, their hurrahs turned into pandemonium.
"I just picked up the ball and put my head down, and honestly blinked," he said.
"Then, I was back on the halfway line, carrying on. The boys really got around me, and it's pretty cool."
Coming from a sporting family where his mum is a former Wallaroo and dad played Aussie Rules, Mickelson was always at a game in Canberra and grew up as a huge Brumbies fan.
So he was already relishing his dream of making his Super Rugby Pacific debut after finding out he was on the team earlier in the week.
"I grew up watching from those stands with mum and dad, smashing hot chips in the cold weather," Mickelson said, after meeting up with the family who'd turned out in force for his big night.
"I just love my footy. And I suppose if he (younger self) knew that I was out there today, it would be a super special feeling."
Coach Stephen Larkham heralded the 23-year-old after his performance, where he played in his less-preferred back row position.
"We know he's a very powerful ball carrier, a very good rugby player. He actually scored two tries in training on Thursday as well," Larkham said.
"It's great to see the local guys come through and stand out on this stage."
The Brumbies now have a bye week, before returning to play bitter rivals NSW Waratahs on May 22, where they'll look to inch closer to a spot in the competition's finals series.