The pair commented on referee David Borbolan's performance during Ireland's 1-1 draw with Austria this month
Both Martin O'Neill and James McClean could face action over their comments made about referee David Borbolan during the Republic of Ireland's 1-1 draw with Austria earlier this month.
As reported by the Irish edition of The Times, the pair could miss Ireland's crucial double header against Georgia and Serbia this September should they be hit with retrospective bans.
"We can confirm that disciplinary proceedings have been opened for such statements," FIFA told the paper in a statement.
"Be informed that two cases were opened: one against James McClean and another one against the coach Martin O’Neill. Please understand that we can’t make any further comments since the matter is ongoing."
After the match, in which Ireland had a late goal disallowed, McClean said: "I know in this day and age the slightest wee thing you say about the referee you get fined and that, but you watched the game, you tell me.
"They [Austria] had a 12th man today. That's all I'll say on that. I'm really disappointed."
Speaking during his post match press conference, O'Neill said: "I'm delighted to have got the equaliser and I thought that we had a legitimate, good goal disallowed.
"The referee wasn't totally to blame for our performance in the first half, but I thought he was very poor in the game.
"Considering he was letting things go during the course of the game — that's fine, I like referees who let things go. But he seemed to be penalising us a great deal."