United have won their opening two Group A games to sit top of the pile, with a double-header against Benfica - bottom of the group - up next.
With FC Basel and CSKA Moscow facing each other twice in the next two gameweeks, four points or more against the Portuguese champions would all but guarantee United a spot in the last-16 of the competition.
Benfica host Manchester United at Estadio da Luz, Lisbon. The match will kick off at 7.45pm on Wednesday 18 October, 2017.
Manchester United will be without Eric Bailly, Michael Carrick, Marouane Fellaini and Paul Pogba for the Champions League clash at Benfica on Wednesday.
Centre-back Bailly missed the weekend draw at Liverpool with an unspecified knock sustained on international duty with the Ivory Coast, while injury setbacks also mean Carrick and Fellaini remain sidelined along with fellow midfielder Pogba.
Marcos Rojo travelled to Portugal but manager Jose Mourinho believes the defender remains two weeks away from returning to full fitness. Zlatan Ibrahimovic is also recovering from knee ligament damage, but Luke Shaw travelled with the team.