Northern Ireland legend Gerry Armstrong says he's disappointed Mark Sykes has switched his allegiance to the Republic of Ireland and he's suggested players can come under pressure before opting to make the move.
Boss Ian Baraclough was stunned when the Oxford United midfielder informed him he didn't wish to be considered for Northern Ireland squads any longer.
The former Glenavon ace played in Baraclough's Under-21 side and had been called up to three Northern Ireland squads by then manager Michael O'Neill but did not play.
Sykes says his heart lies with the Republic but the 23-year-old appeared on the brink of a senior Northern Ireland appearance, and his decision rattled Baraclough and the Irish FA.
Instead of perhaps making his competitive senior international debut in the upcoming Nations League games against Romania and Norway, the Belfast man says he wants to represent the Republic, following in the footsteps of northern players such as James McClean, Shane Duffy and Darron Gibson.
World Cup 1982 hero Armstrong hails from west Belfast and Gaelic football was his first sporting passion before switching to football.
His 63 caps came while playing for five different clubs - Tottenham, Watford, Real Mallorca, West Brom and Chesterfield.
After his football career ended he had two spells as assistant manager of the national team, firstly under Bryan Hamilton (1994-97) and then during Lawrie Sanchez's time in charge (2004-06).
"Fans are frustrated and so am I. If we lose a player at this level it's a blow," said Armstrong.
"At the age of 23 you are asking yourself not why but why now? I don't know why he's made the decision but I do know there are many proud Irishmen in the Northern Ireland team.
"It's also baffling because he played for Ian Baraclough with the Under-21s and Ian showed faith in him, so it doesn't make sense to me. I've no doubt he would have got his chance.
"There can be peer pressure on players. Friends and families can influence the players and you are up against that. Someone might say, 'What are you doing playing in front of a Union Jack or God Save The Queen?'
"I just don't want players to make a mistake, and I said the same to James McClean after talking to Martin O'Neill.
"I can recall Brendan Rodgers' son Anton wanting to play for the Republic and then thinking about coming back. Anton said to me he made a mistake and never felt comfortable. He should have stayed with Northern Ireland and sometimes it can be too late.
"We've lost quite a few players like Shane Duffy and Darron Gibson but, to be honest, they never really did great things."
Sykes, who moved to League One side Oxford in January 2019, won 11 Northern Ireland Under-21 caps.
"When I was elite player mentor we paid a lot of money for the coaches to get the best coaching in the system," added Armstrong.
"We don't have that many players to choose from so when one turns away it's a shame.
"I'm a bit disappointed in Sykesy. Is there any guarantee he will play for the Republic?
"It might not have a huge impact on the squad but it's still disappointing."