Only 16, he was beginning to question whether he did, in fact, have a future in football.
But on Friday night, McNulty returns to what Livingston now call the Tony Macaroni Arena for the first time in almost five years, no longer a callow youth but a fully-fledged Scotland internationalist.
And McNulty’s story, insisted Gary Bollan, the manager who gave him his first-team debut at the West Lothian club, is one that any young player feeling down on their luck should remember.
It may be almost a decade since that day, but it is one Bollan remembers vividly, McNulty stepping from the bench for the last few seconds of a Division Three match against Montrose at Links Park on October 31, 2009, time enough for him to score and wrap up a 3-0 win.
However, as much as Bollan admits to taking a degree of satisfaction at how the career of McNulty – and others he’s managed – has unfolded, he insisted the greatest kudos lay with the player himself.
He said: “Marc had been released by Hibs and, when he was even younger, Celtic. It’s credit to him because he never gave up, he had belief in his own ability and is enjoying the rewards by playing at the level he is now.
“It’s fantastic for other kids, who, at an early stage get a knock in football, can see the confidence Marc had to build himself back up.
“When he came to Livingston, we saw in training he had the ability to score goals. He’d been doing well in the Under-19s so he was due a wee chance for the first team.
“I remember that day. He actually came on for Andy Halliday – another who has gone on to bigger and better things – and, although it was the last minute, he still managed to get a goal.
“Strikers, no matter what age they are, thrive on scoring and it must have been an amazing feeling for him to get that goal – it would have sent his confidence soaring.”
McNulty found his game-time limited both that season and the next but over the next three years established himself as a regular scorer, his goals earning him a six-figure move to Sheffield United in 2014.
Bollan said: “Marc had only just turned 17 when he played at Montrose but, at that age, it’s important that you don’t overplay young players. Going from the Under-19s to the first team is a massive jump. I don’t think a lot of people realise just how big it is.
“We put him in and out of the team to learn gradually, to build him up and allow him to become a regular in the side which, probably, was a springboard to where he is now.”
In those early days McNulty could count on the help of experienced strikers such as Robbie Winters and Kenny Deuchar, Bollan adding: “We had a good squad at the time. Liam Fox was the captain and we brought Mark Fotheringham – who is now my assistant at Cowdenbeath – on board.
“He was great with the young ones. We had a few players who played at a real good level who helped him and others along.”
However, claimed Bollan, as much as McNulty and other youngsters such as the Jacob brothers, Keaghan and Kyle, and Stefan Scougall, were helped by those more experienced players around them, it was the young striker’s own determination and belief in his ability which counted most.
He said: “It has to come from within. If he couldn’t help himself then there was no-one who could help him.
“Did he have a point to prove to others who perhaps doubted his ability? Marc had suffered those knocks but he showed he was no quitter. Having that mentality at a young age is a good tool to have. As a football player, you are always going to take knocks from time to time. It’s how you handle them that counts.
“We had Marc in at 17. There were others who had helped him along the way, but he’s always had that belief, that self-motivation and work ethic.
“But, yes, it is always makes you happy to see young players you’ve had under your wing go on to bigger and better things. It does give you a little bit of satisfaction.”
Wherever he has gone McNulty has scored goals, a fact which doesn’t surprise Bollan, 13 in his first season at Bramall Lane in England’s League One and as many more when on loan at Portsmouth before he was released by the Yorkshire club.
Again, though, Edinburgh-born McNulty simply dusted himself down and got on with it, stepping down to League Two to sign for Coventry City where 28 goals earned him a seven-figure move to Reading in the Championship.
However, it was a move which turned sour, McNulty finding himself on the sidelines despite having clinched a four-year deal as the Royals switched managers, Jose Manuel Gomes replacing Paul Clement and making it clear there was no place for him in his plans.
McNulty’s answer has been to return to the Capital on loan for the remainder of the season with Hibs, seven goals in as many starts not only helping drive Paul Heckingbottom’s side back into the Premiership’s top six, but bringing a personal reward in the shape of a Scotland debut in Kazakhstan followed by a second cap against San Marino as Scotland’s Euro 2020 campaign got off to a shaky start.
Even so, as McNulty himself insisted, it was a proud moment for him and his family, Bollan not surprised in the slightest that the striker’s father Jimmy, brother Kevin and two pals were part of the Tartan Army which descended on San Marino at the weekend to see him replace former Hearts player Callum Paterson after half an hour in the 2-0 win.
He said: “Marc’s dad went everywhere to watch him play. He was at every Livingston game so there would be no way that he’d miss the chance to see him play for Scotland.”