Celtic have applied to Uefa for an exemption to allow Ange Postecoglou to become the club’s new manager.
The Australian does not have the required coaching badges, with European football’s governing body saying the appeal “could take several weeks”.
Celtic are in advanced talks with Postecoglou, who is currently in charge of Yokohama F Marinos in Japan, as they seek a successor to Neil Lennon.
“Mr Postecoglou does not hold the pro licence,” said a Uefa spokesperson.
“A recognition of competence procedure has been initiated. The process could take several weeks.”
The Scottish Premiership club have made the 55-year-old their main target after lengthy negotiations broke down with former Bournemouth boss Eddie Howe.
Greece-born Postecoglou won two A-League titles with Brisbane Roar before a four-year spell as Australia manager from 2013, steering the national team to their first major honour with Asian Cup success in 2015.
Having been appointed by Yokohama in December 2017, he ended the club’s 15-year wait for the J League title in 2019.
Lennon resigned as Celtic manager on 24 February and they club finished the season without a trophy for the first time in 11 years as their pursuit of a 10th successive Scottish title ended in failure.