Rui Vitória has named 22 players in his preliminary squad for Matchweek 4 of the UEFA Champions League. André Almeida and Luisão are both suspended, so Eliseu, Douglas and Jardel have been brought in to bolster Benfica's defensive options.
Filip Krovinović is not registered for European competition, and is replaced by Rafa Silva, who returns to the squad after an absence of three games. Bruno Varela is also included after three matches in the wilderness.
Tuesday night's game at Old Trafford begins at 19:45 local time, and will be officiated by Lithuanian referee Gediminas Mažeika.
Goalkeepers: Svilar, Júlio César and Bruno Varela
Defenders: Lisandro, Grimaldo, Douglas, Eliseu, Jardel and Rúben Dias
Midfielders: Fejsa, Filipe Augusto, Samaris, Živković, Salvio, Pizzi, Cervi, Rafa Silva and Diogo Gonçalves
Forwards: Raúl, Jonas, Gabriel Barbosa and Seferović