Mark Sykes says it was always his 'dream' to play for the Republic of Ireland.
The Oxford United midfielder has changed his international allegiance from Northern Ireland, where he made 11 Under 21 appearances and was named in several senior squads under former boss Michael O'Neill.
He was included on the bench for a Euro 2020 qualifier in Belarus in June 2019. Had he been brought on by O'Neill, it would have permanently tied him to representing Northern Ireland at international level.
However, he didn't make it onto the pitch and so, fast forward 14 months, he has informed O'Neill's successor Ian Baraclough, under whom he made his Under 21 appearances, that he is declaring for the Republic.
Now he has spoken up to explain the move.
“It was a really difficult decision," Sykes told the Oxford United club website.
"I genuinely wish Northern Ireland all the best and know they will do well under their new manager, who I have worked with before and really like.
“The last few weeks have given me time to think about things and I have to do what my heart says.
“The Republic of Ireland are the team I have always dreamed of playing for and I have to try my best to achieve that.
"I am proud to have been involved with the Northern Ireland team, and have always given it my all, but I had to make a choice and it had to be now."
Sykes has impressed since joining Oxford in January last year. Having nailed down a starting spot for Karl Robinson's side, he even scored in the League One play-off final at Wembley last month.
His club boss says that Sykes has 'agonised' over his decision to switch his international allegiance.
"I spoke with Mark and know how tough his decision was," said Robinson. "He has not taken it lightly and he has been agonising over what to do but ultimately he needed to make a choice and as a club we respect his decision.
"He is still a young man, he has a great future ahead of him and he has been very honest over this so all we can do is back him and help him continue to progress as a player.”
United still have a player in the Northern Ireland squad, with Joel Cooper given his first senior call-up after his summer move from Linfield.