The former striker joined the academy from Dublin side Belvedere and had the talent to quickly be elevated into the reserve side, and opportunities in the first-team were not too long in coming round either.

However, he could never quite make an impression at that level and ended up just making the 14 senior appearances for Celtic.

He still forged a decent career, playing for Scottish sides like St Johnstone, Kilmarnock and Dundee while turning out for a host of clubs abroad too.

Looking back, he has identified that he simply did not have strong enough mentality and belief in himself to succeed at Celtic.

“When I look back at all the ones who came through at Celtic and made it – it was a mentality thing," he told the Scottish Sun.

“It was the players who got a chance in the first team and believed they should be there.

“They would say, ‘This is my chance…I’m a first-team player and I am better than the guy I’m coming in for’.

“Personally, I would view it as ‘I am only in because someone is injured’. I would be waiting to be replaced.

“I find that’s the difference between players who go to the top level.

“Those who break in at any of the big clubs and stay for the long term, always have the mentality.

Sheridan was promoting his first ‘In Good Company’ event, where ex-players like Aiden McGeady and James McFadden will be speakers.

McGeady is one who had that mentality to be able to succeed at a big club, while McFadden had the same belief in himself at Motherwell and then Everton.

“There are players, like Aiden and Faddy, who have ridiculous talent, but they also had the belief," added the Irishman.

“It’s one thing being a teenage prodigy, but if you don’t have the mindset to go with the talent then you won’t make the most of your career.

“I remember chatting to Aiden when I had six months left at the end of a contract.

“I said something like, ‘I’m really going to step it up so that I can get a good move’ and his reaction was, ‘Why are you not always like that?’

“It’s true. You shouldn’t be switching it on and off. Aiden had so much talent but he also put the extra work in that people didn’t see.”