Michael Carrick's team were controversially beaten in their derby clash with Manchester City over the weekend as Erling Haaland's second-half goal sealed a 1-0 win for Enzo Maresca's visitors.
That continues United's inconsistent start to the 2026/27 campaign and a clash with Brighton - who have won on four of their last five visits to Old Trafford - could pose a real test for Carrick and his rotated squad.
Man United v Brighton team news
Carrick will follow the pattern of several top-flight managers and make several changes to his regular starting XI with Leny Yoro and Ayden Heaven tipped to start at centre-back.
16-year-old star JJ Gabriel will not feature for his debut, amid rumours he's asked to leave the club, and Benjamin Sesko could lead the attack.
Luke Shaw missed the City game with a minor injury, and Carrick confirmed he'll make a late call on the England international, with Amad Diallo, Matthijs de Ligt and Carlos Baleba all still out.
Man United v Brighton predicted lineups
Man United XI: Darlow; Dalot, Heaven, Yoro, Shaw; Santos, Mainoo, Mount; Mbeumo, Sesko, Rashford.
Man United v Brighton kick off time
Kick off at Old Trafford is set for 8pm UK time.
Key stat
From those four wins away at United for Brighton, Pascal Gross has been the player to watch for the Seagulls, with three goals scored at Old Trafford.