O'Hagan is somewhat of a late developer, having primarily played Gaelic games during his youth, before taking up rugby in his late teens, as he explains:
"I mostly played Gaelic football and hurling for my local club in Swatragh and in school at St Patrick's Maghera. A couple of friends from Magherafelt invited me over to Rainey to play rugby one Saturday for a bit of craic and it sort of took off from there. At that stage I just thought it would help with my fitness during the GAA off-season."
It was at Rainey Old Boys that O'Hagan honed his skills under the tutelage of club coaches, before his strong ball carrying and robust scrummaging caught the eye of the Kingspan Stadium coaching personnel.
"When I first started at Rainey, Damian Campbell and Seamie Higgins helped me out a lot. Because I was transferring from Gaelic games to rugby it was hard to get the scrummaging technique going, so Damian in particular always gave me a lot of advice. It wasn't until senior rugby over the past couple of years that I've got really focused and that's when John Andrews pushed me on and tested me. He drove me on a bit more."
While schools' rugby would've been perceived as the traditional route for a young player to join the provincial Academy setup, O'Hagan is one of three current Ulster Academy players who have entered the programme via club rugby. As Provincial Talent Coach Michael Black states, the increase in players joining the Academy from club and youth rugby is no coincidence, and it is a trend that he expects to continue:
"As part of our talent identification process, we are keen to explore all avenues for players to join our development programme. It is no longer just about looking at players involved in Schools' Cup rugby or within the greater Belfast area.
"The development of indigenous talent throughout the Province is a critical element of our long term succession planning model so we are delighted to see the likes of Tommy, Adam McBurney and Aaron Hall progressing well within the Academy structure after making their initial impression at club level.
"John McCusker is another example of the talent that is developing from Club Youth Rugby. The second row forward is still only 18 and eligible for club U18 rugby, but has played most of this year in the Ulster Bank All-Ireland League with Rainey 1st XV, and already been capped at 'A' level in the B&I Cup this season."
This sentiment is echoed by Ulster Carpets, sponsors of youth rugby within the Province, as Managing Director Nick Coburn comments:
"We are extremely proud of our sponsorship of Ulster Youth Rugby where the focus is on progression and improvement, and this fits well with Ulster Carpets' culture of innovation and pursuit of excellence. We have seen substantial progress in the Ulster Youth programme during our partnership and are delighted to see the development of youth players into the Academy setup."
As for O'Hagan, he's intent on making the most of his opportunities and enjoying the experiences along the way.
"This time last year I never thought that I'd be starting for the A's never mind getting man of the match in a British & Irish Cup game. That was unbelievable for me.
"I'm still relatively new to this game but I'm learning every day. The support staff here are excellent. Every session I get feedback from them, then I take that into the next training session, which is brilliant for me because I have a lot of things to work on and it's going to help me big time.
"For now, the focus is making sure I'm in the squad for the B&I Cup quarter-final against Munster and going into that game like a man possessed, make a big statement, try to win the game, then push on as far as we can in the competition."