The 19-year-old winger was given an unexpected chance to show what he can do at Celtic Park in the Premiership clash with Motherwell when striker Odsonne Edouard hobbled off in the first-half with an abductor injury.
He’s been earmarked as one of the club’s most promising up-and-coming players for several seasons now, and it wasn’t long before Johnston had his first senior goal, as his brilliant effort kissed the underside of the crossbar before dropping into the back of the net.
Speaking via STV after the 3-0 victory, Johnston admitted he was ‘buzzing’ with the goal, but it turns out his mum and dad probably enjoyed the strike even more than he did.
The teenager explained: “It’s my first competitive goal, I’ve been waiting a while to get it so I’m just buzzing to finally get off the mark.
“It had been playing on my mind, so I’m just happy to get it out of the way.
“I didn’t even realise it had hit the net.
“My parents were up in the players’ box, a few of the boys said they were going mental so I’m buzzing.
“I’ll play where I’m told, as long as I’m getting games I don’t mind.
“I’m just taking it day-by-day and I’m working hard to earn a place in the team.
“If I can get in playing as a striker, that’s fine, if I’m playing elsewhere it doesn’t matter.
“My preferred position is as a winger but I can play up-front, if that’s where I’m asked to play I’ll just go on and work hard.
“Celtic, as a club, always want to play young players so hopefully I can take my chance.”
With Edouard struggling to be fit, and Leigh Griffiths out for the foreseeable future with personal problems, could Johnston become a crucial player for the Hoops this month?