KAA Gent – West Ham United
Referee: Anastasios Sidiropoulos (GRE, photo)
Assistant Referee 1: Polychronis Kostaras (GRE)
Assistant Referee 2: Lazaros Dimitriadis (GRE)
Fourth Official: Vassilis Fotias (GRE)
VAR: Angelos Evangelou (GRE)
AVAR: Aristotelis Diamantopoulos (GRE)
Referee Observer: William Young (SCO)
Lech Poznan – ACF Fiorentina
Referee: Irfan Peljto (BIH)
Assistant Referee 1: Senad Ibrisimbegović (BIH)
Assistant Referee 2: Davor Beljo (BIH)
Fourth Official: Miloš Gigovic (BIH)
VAR: Fedayi San (SUI)
AVAR: Ivan Bebek (CRO)
Referee Observer: Stefan Johannesson (SWE)
RSC Anderlecht – AZ Alkmaar
Referee: Daniel Siebert (GER)
Assistant Referee 1: Jan Seidel (GER)
Assistant Referee 2: Rafael Foltyn (GER)
Fourth Official: Daniel Schlager (GER)
VAR: Harm Osmers (GER)
AVAR: Sören Storks (GER)
Referee Observer: Volodymyr Petrov (UKR)
FC Basel – OGC Nice
Referee: Glenn Nyberg (SWE)
Assistant Referee 1: Mahbod Beigi (SWE)
Assistant Referee 2: Andreas Söderqvist (SWE)
Fourth Official: Adam Ladebäck (SWE)
VAR: Stuart Attwell (ENG)
AVAR: Peter Bankes (ENG)
Referee Observer: Michael Ross (NIR)