Olympiakos – West Ham United
Referee: Andris Treimanis LVA (photo)
Assistant Referee 1: Haralds Gudermanis LVA
Assistant Referee 2: Aleksejs Spasjonņikovs LVA
Fourth Official: Aleksandrs Golubevs LVA
VAR: Dennis Higler NED
AVAR: Kristaps Ratnieks LVA
Referee Observer: Terje Hauge NOR
TSC Bačka Topola – SC Freiburg
Referee: Aliyar Aghayev AZE
Assistant Referee 1: Zeynal Zeynalov AZE
Assistant Referee 2: Akif Amirali AZE
Fourth Official: Kamal Umudlu AZE
VAR: Alper Ulusoy TUR
AVAR: Abdulkadir Bitigen TUR
Referee Observer: Uno Tutk EST
Olympique de Marseille – AEK Athens
Referee: Daniel Stefanski POL
Assistant Referee 1: Dawid Golis POL
Assistant Referee 2: Michal Obukowicz POL
Fourth Official: Damian Sylwestrzak POL
VAR: Tomasz Kwiatkowski POL
AVAR: Pol van Boekel NED
Referee Observer: Stefan Messner AUT
Sparta Praha – Rangers FC
Referee: Sascha Stegemann GER
Assistant Referee 1: Christian Dietz GER
Assistant Referee 2: Christof Günsch GER
Fourth Official: Florian Badstübner GER
VAR: Sören Storks GER
AVAR: Pascal Müller GER
Referee Observer: Dejan Filipović SRB
Aris Limassol – Real Betis
Referee: Filip Glova SVK
Assistant Referee 1: Daniel Polaček SVK
Assistant Referee 2: Peter Bednar SVK
Fourth Official: Boris Marhefka SVK
VAR: Michal Očenaš SVK
AVAR: Edwin van de Graaf NED
Referee Observer: Emil Božinovski MKD
Sturm Graz – Atalanta BC
Referee: Duje Strukan CRO
Assistant Referee 1: Bojan Zobenica CRO
Assistant Referee 2: Alen Jakšić CRO
Fourth Official: Dario Bel CRO
VAR: Ivan Bebek CRO
AVAR: Nejc Kajtazovič SVN
Referee Observer: Rune Pedersen NOR
Rakow Czestochowa – Sporting CP
Referee: Anastasios Papapetrou GRE
Assistant Referee 1: Tryfon Petropoulos GRE
Assistant Referee 2: Iordanis Aptosoglou GRE
Fourth Official: Andreas Gamaris GRE
VAR: Angelos Evangelou GRE
AVAR: Aristotelis Diamantopoulos GRE
Referee Observer: Vlado Svilokos CRO
Molde FK – BK Häcken
Referee: Urs Schnyder SUI
Assistant Referee 1: Marco Zürcher SUI
Assistant Referee 2: Benjamin Zürcher SUI
Fourth Official: Sven Wolfensberger SUI
VAR: Fedayi San SUI
AVAR: Esther Staubli SUI
Referee Observer: Joao Ferreira POR
Brighton & Hove Albion – AFC Ajax
Referee: Bartosz Frankowski POL
Assistant Referee 1: Marcin Boniek POL
Assistant Referee 2: Jakub Winkler POL
Fourth Official: Patryk Gryckiewicz POL
VAR: Piotr Lasyk POL
AVAR: Massimiliano Irrati ITA
Referee Observer: Lucilio Batista POR
Union St. Gilloise – LASK Linz
Referee: Atilla Karaoglan TUR
Assistant Referee 1: Ceyhun Sesigüzel TUR
Assistant Referee 2: Cevdet Kömürcüoglu TUR
Fourth Official: Cagdas Altay TUR
VAR: Carlos Del Cerro Grande ESP
AVAR: Ricardo De Burgos Bengoetxea ESP
Referee Observer: Martin Hansson SWE
Liverpool FC – Toulouse FC
Referee: Rade Obrenovič SVN
Assistant Referee 1: Jure Praprotnik SVN
Assistant Referee 2: Grega Kordež SVN
Fourth Official: David Šmajc SVN
VAR: Christian Dingert GER
AVAR: Marco Fritz GER
Referee Observer: Alexandru Deaconu ROU
Panathinaikos – Stade Rennais
Referee: Joao Pinheiro POR
Assistant Referee 1: Bruno Jesus POR
Assistant Referee 2: Luciano Maia POR
Fourth Official: Fabio Verissimo POR
VAR: Luis Godinho POR
AVAR: Andre Narciso POR
Referee Observer: Leslie Irvine NIR
AS Roma – Slavia Praha
Referee: Espen Eskas NOR
Assistant Referee 1: Jan Engan NOR
Assistant Referee 2: Isaak Bashevkin NOR
Fourth Official: Kristoffer Hagenes NOR
VAR: Bastian Dankert GER
AVAR: Benoît Millot FRA
Referee Observer: David Fernandez Borbalan ESP
Sheriff Tiraspol – Servette FC
Referee: John Brooks ENG
Assistant Referee 1: Neil Davies ENG
Assistant Referee 2: James Mainwaring ENG
Fourth Official: Darren England ENG
VAR: David Coote ENG
AVAR: Christopher Kavanagh ENG
Referee Observer: Manuel Diaz Vega ESP
Bayer Leverkusen – Qarabag FK
Referee: Horațiu Feșnic ROU
Assistant Referee 1: Valentin Avram ROU
Assistant Referee 2: Alexandru Cerei ROU
Fourth Official: Szabolcs Kovacs ROU
VAR: Tiago Martins POR
AVAR: Paolo Valeri ITA
Referee Observer: Stavros Tritsonis GRE