Roy Keane is in talks to become the new Celtic manager and should be appointed before the Ireland team fly to America on Wednesday.
The Irish number two has already held preliminary talks with Celtic owner Dermot Desmond.
He has also spoken to the FAI about an early release from his contract as assistant manager to Martin O'Neill.
Both O'Neill and the FAI are reluctant to lose Keane before the start of Ireland's European Championship qualifying bid in September.
But O'Neill admitted at a Thursday press conference that contact had already been made by Celtic with their former player.
O'Neill said: "I had a call the other day from Dermot Desmond wanting to speak to Roy if it was at all possible, and I mentioned it to Roy, of course.
"I am sure he was wanting to have chat anyway because a club like Celtic might not come around too often.
"It was just a really informal chat, I think, but if you are asking me would I be really disappointed? Of course if Roy was to leave us.
A statement said: "Following speculation concerning the manager's position at Celtic, the club can confirm that it is currently continuing its discussions with a number of excellent candidates.
"We will continue this process and select who we regard as the best appointment for Celtic. We will update our supporters as soon as this process is complete."