Arsenal manager Unai Emery looks dejected during the Europa League match in Group F between Arsenal and Eintracht Frankfurt at Emirates Stadium, London, Britain, November 28, 2019. Emery defends his team's performance in a press conference after his team lost 1-2 to Eintracht Frankfurt in the Europa League at home. REUTERS/Eddie Keogh

Arsenal manager Unai Emery gestures during the Europa League match in Group F between Arsenal and Eintracht Frankfurt at Emirates Stadium, London, Britain, November 28, 2019. Emery defends his team's performance in a press conference after his team lost 1-2 to Eintracht Frankfurt in the Europa League at home. Reuters/Paul Childs

Arsenal manager Unai Emery gestures during the Europa League match in Group F between Arsenal and Eintracht Frankfurt at Emirates Stadium, London, Britain, November 28, 2019. Emery defends his team's performance in a press conference after his team lost 1-2 to Eintracht Frankfurt in the Europa League at home. REUTERS/Eddie Keogh

Arsenal manager Unai Emery during the Europa League match in Group F between Arsenal and Eintracht Frankfurt at Emirates Stadium, London, Britain, November 28, 2019. Emery defends his team's performance in a press conference after his team lost 1-2 to Eintracht Frankfurt in the Europa League at home. Reuters/Paul Childs

Arsenal manager Unai Emery during the Europa League match in Group F between Arsenal and Eintracht Frankfurt at Emirates Stadium, London, Britain, November 28, 2019. Emery defends his team's performance in a press conference after his team lost 1-2 to Eintracht Frankfurt in the Europa League at home. Reuters/Paul Childs

Arsenal's Granit Xhaka with manager Unai Emery during the Europa League match in Group F between Arsenal and Eintracht Frankfurt at Emirates Stadium, London, Britain, November 28, 2019. Emery defends his team's performance in a press conference after his team lost 1-2 to Eintracht Frankfurt in the Europa League at home. REUTERS/Eddie Keogh