The Manchester City loanee joined for a two-year period in the summer transfer window, though it appears he will have to bide his time before becoming a first-team regular.
Senior squad members Scott Allan and Marvin Compper also found themselves omitted from the squad.
The latter has seldom been seen in a Celtic jersey since making a £1million move from RB Leipzig in January, while Allan continues to find his opportunities at Parkhead limited after failing to find a move away from the club in the summer window.
Europa League squads are broken down into two “lists”: List A and List B. The former can only have a maximum of 25 players. The latter can be unlimited.
To qualify for List B a player be “born on, or after, 1 January 1997 and has been eligible to play for the club concerned for any uninterrupted period of two years since his 15th birthday (players aged 16 may be submitted if they have been registered with the club for the previous two years).”
The full Celtic squad is as follows. Players with an asterik next to their name qualify through List B.
Craig Gordon, Scott Bain, Conor Hazard*, Ryan Mullen*
Kieran Tierney*, Emilio Izaguirre, Kristoffer Ajer, Jack Hendry, Jozo Simunovic, Cristian Gamboa, Dedryck Boyata, Mikael Lustig, Filip Benkovic, Anthony Ralston*, Daniel Church*, Wallace Duffy*, Kerr McInroy*, Stephen Welsh*, Lewis Bell*
Scott Brown, Scott Sinclair, Lewis Morgan, Tom Rogic, Olivier Ntcham, Youssuf Mulumbu, Callum McGregor, James Forrest, Eboue Kouassi, Ewan Henderson*, Scott Robertson*, Paul Kennedy*, Ross McLaughlin*, David Mckay*, Kristie Marku*, Mark Hill*, Kieran Mcgrath*, Regan Hendry*
Leigh Griffiths, Jonny Hayes, Ryan Christie, Odsonne Edouard, Michael Johnston*, Grant Savoury*