Republic of Ireland boss Martin O'Neill labelled Ronald Koeman a "master tactician of the blame game" as their row over James McCarthy's fitness escalated on Friday.
McCarthy, 26, missed Everton's past two matches but linked up with the Republic squad in the international break.
He suffered a recurrence of a hamstring injury, ruling him out of Saturday's derby at Liverpool.
Toffees boss Koeman had accused O'Neill of "not protecting" the midfielder.
In his news conference on Friday, a clearly angered Koeman read out a prepared statement in which he added: "Clearly James was not fit to play.