UEFA Europa League – Quarter-finals (First Leg)

11 April 2019

Arsenal FC – SSC Napoli
Referee: Alberto Undiano Mallenco (ESP, photo)
Assistant Referee 1: Raul Cabanero Martinez (ESP)
Assistant Referee 2: Inigo Prieto Lopez (ESP)
Fourth Official: Diego Barbero Sevilla (ESP)
Additional AR 1: Xavier Estrada Fernandez (ESP)
Additional AR 2: Jose Munuera Montero (ESP)
Referee Observer: Stefan Messner (AUT)

Villarreal – Valencia
Referee: Michael Oliver (ENG)
Assistant Referee 1: Stuart Burt (ENG)
Assistant Referee 2: Simon Bennett (ENG)
Fourth Official: Constantine Hatzidakis (ENG)
Additional AR 1: Craig Pawson (ENG)
Additional AR 2: Andre Marriner (ENG)
Referee Observer: Alexandru Deaconu (ROU)

SL Benfica – Eintracht Frankfurt
Referee: Anthony Taylor (ENG)
Assistant Referee 1: Gary Beswick (ENG)
Assistant Referee 2: Adam Nunn (ENG)
Fourth Official: Lee Betts (ENG)
Additional AR 1: Stuart Attwell (ENG)
Additional AR 2: Martin Atkinson (ENG)
Referee Observer: Terje Hauge (NOR)

Slavia Praha – Chelsea FC
Referee: Felix Zwayer (GER)
Assistant Referee 1: Thorsten Schiffner (GER)
Assistant Referee 2: Marco Achmüller (GER)
Fourth Official: Eduard Beitinger (GER)
Additional AR 1: Daniel Siebert (GER)
Additional AR 2: Sascha Stegemann (GER)
Referee Observer: Haim Jakov (ISR)