Manager Erik ten Hag has confirmed that Luke Shaw (calf), Tyrell Malacia (knee), Leny Yoro (foot) and Rasmus Hojlund (hamstring) all remain sidelined, while Victor Lindelof is nursing a toe injury and will also miss this weekend's fixture.
After Man United kept a clean sheet in a 1-0 opening win over Fulham last Friday, Ten Hag will consider sticking with the same back four of Noussair Mazraoui, Harry Maguire, Lisandro Martinez and Diogo Dalot, meaning new signing Matthijs de Ligt could once again begin as a substitute.
Amidst speculation that the Red Devils are close to signing Manuel Ugarte from Paris Saint-Germain, Casemiro and Kobbie Mainoo are expected to link arms in midfield once again.
Amad Diallo and Marcus Rashford both started against Fulham and are in contention to keep their places in the first XI, although Alejandro Garnacho will be pushing to start ahead of either winger against Brighton.
Bruno Fernandes operated as a false nine last time out, but he could move into his favoured No.10 role to allow Joshua Zirkzee to lead the line after he came off the bench to score the winning goal on his Premier League debut against Fulham.
The inclusion of Zirkzee could therefore see Mason Mount drop to the substitutes bench, providing cover along with the likes of Antony, Scott McTominay, Christian Eriksen and Jonny Evans.
Manchester United possible starting lineup: Onana; Mazraoui, Maguire, Martinez, Dalot; Casemiro, Mainoo; Amad, Fernandes, Garnacho; Zirkzee