Celtic could be thrown a Champions League lifeline.
The Bhoys might be reinstated in the competition as their qualifying round opponents Legia Warsaw might have fielded an ineligible player during the 2-0 loss at Murrayfield.
Bartosz Bereszynski came on as a sub four minutes from time but it appears - despite missing three matches - he was still officially suspended after a red card last season as he hadn't been listed in a matchday squad as required under UEFA rules.
Celtic were hammered off the park 6-1 over the two legs by Legia.
The Bhoys are in familiar territory as they made it into the Europa League three years ago after Swiss side Sion were found to have fielded five ineligible players.
