He was out on the playing fields of fields Coatbridge yesterday, with Celtic and the Gaelic Athletic Association launching an initiative at St Ambrose High School. O'Connell, at 18, can already look back on school days with the quiet satisfaction of someone who knows that the future holds promise even if that, as always in football, carries more than a hint of uncertainty.
His Celtic career has, of course, already taken its first significant step. O'Connell made his debut against Ross County last month and he thus followed in the footsteps of Roy Keane, another Corkman.
"I met him a few times when I was younger," says O'Connell. "I went to one of his book signings. He's obviously a legend. Everyone in Cork looks up to him for what he's done in the game."
O'Connell was brought up in the GAA fold, playing both Gaelic football and hurling. He only stopped at 15 when his prowess at what the Irish call soccer ensured a move to Celtic.
"I wouldn't have minded playing in the All-Ireland final," he says of the signature day at Croke Park for both Gaelic football and hurling, "but this is the path I've chosen."
He has walked it with some purpose, emboldened by the physical and mental lessons learned from his boyhood games. "I learned a lot playing Gaelic football from coaches and my team-mates. It gave me valuable experience," he says.
The youth leadership programme, organised jointly by Celtic and the GAA, will take place across North Lanarkshire, Inverclyde and Glasgow. The camps aim to bring together children from differing sporting and cultural backgrounds using coaching in Gaelic games and association football.
O'Connell has grown in another way, moulded by his immersion in professional sport. He has been helped significantly by two figures: Jim McGuiness, the manger who took the Donegal Gaelic football side to an All-Ireland title, and Neil Lennon, whose sporting accomplishments include being selected for the Armagh minor team.
McGuinness was appointed by Celtic as a performance consultant in 2012 and O'Connell says of his countryman: "He's been quite heavily involved in the development squad we're working in. His name speaks for itself in Gaelic terms. He works on the psychological stuff with us. The way he works is on the off the field stuff, working on your focus.
"You can't really 'practise' focus but it's about getting into your head and emphasising how important all this is to you. You have to switch your focus on to playing games and training. That's what he's worked on."
O'Connell has grown into a strong, capable defender and his progress was rewarded with that first-team nod from his manager. "It's been a bit surreal but I've enjoyed it," he says of the reaction to his debut. "I'm just trying to keep my feet on the ground."
He says of Lennon: "The manager is very good with the younger players. Me and Hendo [Liam Henderson] have been around for a while so we've been training a lot with the first team. We know how to take to him and he's been very good with us. He's helped us along."
Of course, O'Connell is now at ease in his place of work. "I've been here a few years now so I'm used to life over here but he's been very good with me since I've come through. He's given the lads a few opportunities and you can't argue with that."
His words are cautious but his ambition is undimmed. "I just have to keep working hard and see where it takes me," he says. "I'll be doing my bit and working as hard as I can to catch his eye again. The progress of people like James Forrest shows that if you work hard and you're good enough, the manager will give you a chance. That's what everyone in the youth set-up looks at."
O'Connell, too, looks to Virgil van Dijk for both inspiration and advice. Only four years older than O'Connell, the impressive Dutchman is being advanced for a place in his country's World Cup side by both Co Adriaanse, the former Ajax manager, and Pierre van Hooijdonk, the former Celtic striker and Dutch internationalist.
"Van Dijk is a good option for Holland," said Adriaanse. "He has the height, the build, the temperament and the speed for that position [centre-half]. He has been consistently good for Celtic and he is also a threat at set-pieces. I believe Holland would have a good defensive partnership with Virgil van Dijk and Terence Kongolo of Feyenoord."
Van Hooijdonk said: "In Scotland, everyone is saying van Dijk will go to an English club this summer. He deserves an opportunity for the national side."
O'Connell was impressed with van Dijk when he played alongside him against Ross County. "He's tremendous. He makes the game look easy most of the time. Even in the Champions League games he was arguably the best player on the pitch. I don't see why he shouldn't go to the World Cup," he says.
"Playing with him, he oozes confidence. He talked me through the whole game. The way he plays the game is beyond his years. You have to look at him as an example, the way he's progressed through the season has been fantastic."