Does he want to continue playing for Ireland?
He never seems to come out and say it, so maybe he's just decided to make the best of his final couple of years in club football and retire
Might sound crazy, but if Cullen is banned from the first Nations League game (and I don't see why he will be, it's a completely different competition from the WC), might be consider using the March games to have a look at someone else.. perhaps even the likes of Collins in the defensive midfield role?