While Leny Yoro and Tyrell Malacia continue to work their way back from respective foot and knee injuries, Harry Maguire has been ruled out for a "few weeks" after suffering a muscle injury in the 0-0 draw with Aston Villa prior to the international break.
The Red Devils could also be without the services of full-back Noussair Mazraoui, who recently underwent an operation to address heart palpitations.
Erik ten Hag has been dealt a fresh injury concern regarding midfielder Manuel Ugarte, who limped off with an unspecified issue on international duty with Uruguay on Tuesday night.
Ugarte is set to be assessed along with injury-riddled Luke Shaw (calf), Mason Mount (knock), Kobbie Mainoo (hamstring), Alejandro Garnacho (knee) and Amad Diallo (illness), the latter three all withdrew from international duty earlier this month.
With Man United currently light in the full-back department, it has been reported that Ten Hag could use Jonny Evans at left-back, with Diogo Dalot moving over to the right side of a back four, while Lisandro Martinez and Matthijs de Ligt could both be recalled to start at centre-back.
Casemiro, Christian Eriksen and Bruno Fernandes are all in contention to start in midfield, while Marcus Rashford is expected to start on the left flank as either Garnacho, Diallo - if fit - or Antony operates on the right.
Rasmus Hojlund, who allegedly picked up a knock on international duty last weekend, should be fit to feature on Saturday after playing for just under an hour for Denmark on Tuesday, but Ten Hag may instead hand Joshua Zirkzee a start up front against Brentford.
Manchester United possible starting lineup: Onana; Dalot, De Ligt, Martinez, Evans; Eriksen, Casemiro; Garnacho, Fernandes, Rashford; Zirkzee