The reigning Portuguese champions travel to Old Trafford two weeks after an error from the tournament's youngest ever goalkeeper, 18-year-old Mile Svilar, allowed Marcus Rashford's speculative second-half free-kick to condemn the 10-man hosts to a 1-0 defeat in Lisbon.
Long-serving captain Luisao was dismissed for a second bookable offence during the dying embers of that dull clash at the Estadio da Luz, meaning he will be unavailable for the return fixture in Manchester.
Versatile full-back Andre Almeida also remains suspended after his dismissal for an awful tackle in the shock 5-0 thrashing by FC Basel on matchday two.
However, Barcelona loanee Douglas was named in Benfica's 22-man preliminary squad list after missing Friday night's 1-0 Primeira Liga defeat of Feirense with a sprained ankle.
The Brazilian right-back has made just two appearances for the club since joining on a season-long loan in late August as a replacement for Nelson Semedo, featuring in the initial tie against United and in the Taca de Portugal third round victory over Olhanense.
Defenders Eliseu and Jardel, forward Rafa and third-string goalkeeper Bruno Varela also earn recalls, although, as reported by Portuguese publication A Bola, Filip Krovinovic, the Croatian midfielder signed from Rio Ave in June, is not currently eligible for European competition.
With those losses to Basel and Jose Mourinho's United preceded by a 2-1 home defeat at the hands of CSKA Moscow, Benfica, who reached the Champions League round of 16 last year before being dispatched by Borussia Dortmund, currently sit bottom of Group A with zero points from their opening three fixtures. They have scored just one goal and conceded eight.
United, meanwhile, have won all three of their matches since returning to the continent's premier club competition following a one-year absence by winning the Europa League in 2016-17. The 20-time English champions can book their spot in the first knockout phase if they maintain that 100% record on Tuesday and CSKA fail to beat Basel in Switzerland.
Former Benfica boss Mourinho is expected to remain without Zlatan Ibrahimovic, Marouane Fellaini (both knee) and Michael Carrick (calf) for the visit of his former employers, while he still claims to have "no idea" when Paul Pogba will be in a position to return from his hamstring problem. Marcos Rojo is expected to be ready to feature after the upcoming international break after his recovery from significant knee ligament damage.
22-man preliminary Benfica squad for Manchester United trip
Goalkeepers: Svilar, Julio Cesar, Bruno Varela
Defenders: Lisandro, Grimaldo, Douglas, Eliseu, Jardel, Ruben Dias
Midfielders: Fejsa, Filipe Augusto, Samaris, Zivkovic, Salvio, Pizzi, Cervi, Diogo Goncalves
Forwards: Gabriel Barbosa, Jonas, Rafa, Raul, Seferovic