The Hoops have until the end of Thursday, August 13, to submit their initial squad list for the play-off round. UEFA’s rules allow clubs to make changes to their squad after the initial list has been submitted. So even if Hassan misses Thursday’s initial deadline, Celtic still have another opportunity to get him involved. Celtic’s Champions League registration datesThursday, August 13: Deadline to submit the initial squad list for the play-off. Deadline to submit the initial squad list for the play-off.