Rayo Vallecano – AEK Athens
Referee: Benoît Bastien FRA (photo)
Assistant Referee 1: Hicham Zakrani FRA
Assistant Referee 2: Aurélien Berthomieu FRA
Fourth Official: Jérémie Pignard FRA
VAR: Bram Van Driessche BEL
AVAR: Bastien Dechepy FRA
Referee Observer: László Vagner HUN
FSV Mainz – RC Strasbourg
Referee: Rade Obrenovič SVN
Assistant Referee 1: Jure Praprotnik SVN
Assistant Referee 2: Grega Kordež SVN
Fourth Official: Martin Matoša SVN
VAR: Matej Jug SVN
AVAR: Alen Borošak SVN
Referee Observer: Michael Argyrou CYP
Crystal Palace – AC Fiorentina
Referee: Donatas Rumšas LTU
Assistant Referee 1: Aleksandr Radiuš LTU
Assistant Referee 2: Dovydas Sužiedėlis LTU
Fourth Official: Manfredas Lukjančukas LTU
VAR: Rob Dieperink NED
AVAR: Erwin Blank NED
Referee Observer: Itchko Lozev BUL
Shakhtar Donetsk – AZ Alkmaar
Referee: Nicholas Walsh SCO
Assistant Referee 1: Francis Connor SCO
Assistant Referee 2: Daniel McFarlane SCO
Fourth Official: Donald Robertson SCO
VAR: Stuart Attwell ENG
AVAR: Kevin Clancy SCO
Referee Observer: Darko Čeferin SVN
