The Spanish referee Carlos del Cerro Grande will officiate Olympiacos-Atalanta, the first leg of the 2021-2022 UEFA Europa League knockout round playoffs. His assistants will be Juan Carlos Yuste (ESP) and Roberto Alonso Fernández (ESP), fourth official: Javier Alberola Rojas (ESP), V.A.R. Juan Martínez Munuera (ESP), A.V.A.R. Guillermo Cuadra Fernández (ESP).
