MARK Sykes says he has followed his heart by making a tough decision to change his international allegiance.

The Oxford United midfielder earned 11 caps at under 21 level for Northern Ireland, but has not made his debut at senior level and informed new manager Ian Baraclough at the weekend he did not want to be selected.

It is a decision which left his former under 21 manager "disappointed" and "surprised".

Teammate Joel Cooper has though been included for the first time.

Instead, he plans to make himself available for the Republic of Ireland, who reportedly made contact earlier in the summer.

The 23-year-old was not included in the squad for matches next month which was announced today, but it is likely to be down to the administrative issues involved in transferring from one country to another.

“It was a really difficult decision," Sykes told the 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.”

Boss Karl Robinson added: "Mark 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.”