The Scottish Football Association have written to Celtic manager Neil Lennon asking him to explain comments that he has made ahead of Sunday's league match against St Johnstone.
It is the third time in just over a week that the SFA's compliance officer Vincent Lunny has written to the Irishman.
Ahead of the match at Parkhead, Lennon said: "It will be nice just to be able to go out and think only about winning a game of football - and maybe have a decent refereeing performance into the bargain."
It is against SFA rules that were implemented at the start of the season to talk about officials before a match.
Lennon has until Friday to respond.