UEFA Europa League – Semi-finals (First Leg)

2 May 2019

Arsenal – Valencia
Referee: Clement Turpin (FRA, photo)
Assistant Referee 1: Nicolas Danos (FRA)
Assistant Referee 2: Cyril Gringore (FRA)
Fourth Official: Hicham Zakrani (FRA)
Additional AR 1: Benoît Bastien (FRA)
Additional AR 2: Ruddy Buquet (FRA)
Referee Observer: Francesco Bianchi (SUI)

Eintracht Frankfurt – Chelsea FC
Referee: Carlos Del Cerro Grande (ESP)
Assistant Referee 1: Juan Yuste Jimenez (ESP)
Assistant Referee 2: Roberto Alonso Fernandez (ESP)
Fourth Official: Raul Cabanero Martínez (ESP)
Additional AR 1: Jesus Gil Manzano (ESP)
Additional AR 2: Jose Sanchez Martínez (ESP)
Referee Observer: Jaap Uilenberg (NED)