15 April 2021
Slavia Praha – Arsenal FC
Referee: Cüneyt Cakir (TUR, photo)
Assistant Referee 1: Bahattin Duran (TUR)
Assistant Referee 2: Tarik Ongun (TUR)
Fourth Official: Arda Kardesler (TUR)
VAR: Abdulkadir Bitigen (TUR)
AVAR: Mete Kalkavan (TUR)
Referee Observer: Laurent Duhamel (FRA)
Villarreal CF – GNK Dinamo
Referee: Danny Makkelie (NED)
Assistant Referee 1: Hessel Steegstra (NED)
Assistant Referee 2: Jan de Vries (NED)
Fourth Official: Allard Lindhout (NED)
VAR: Kevin Blom (NED)
AVAR: Jochem Kamphuis (NED)
Referee Observer: Karen Nalbandyan (ARM)
AS Roma – AFC Ajax
Referee: Anthony Taylor (ENG)
Assistant Referee 1: Gary Beswick (ENG)
Assistant Referee 2: Adam Nunn (ENG)
Fourth Official: David Coote (ENG)
VAR: Stuart Attwell (ENG)
AVAR: Paul Tierney (ENG)
Referee Observer: Darko Čeferin (SVN)
Manchester United – Granada CF
Referee: Istvan Kovacs (ROU)
Assistant Referee 1: Vasile Marinescu (ROU)
Assistant Referee 2: Ovidiu Artene (ROU)
Fourth Official: Sandro Schärer (SUI)
VAR: Bastian Dankert (GER)
AVAR: Pawel Gil (POL)
Referee Observer: Sandor Piller (HUN)