Manchester United's past memories against Brighton are not pleasant. Manchester United have lost three of their last five matches against Brighton. So there is no chance to say for sure that United will win against Brighton in the next match.
Manchester United's squad is strong. But the Brighton team is not weak. This group is also quite strong. Brighton did not perform well last season. So this season the team is trying its best to form a stable squad. I saw the performance of the Brighton players in the first match against Everton. An excellent 3-0 win for Brighton. Brighton will also play at home against Manchester United. Players will be more confident at home. So I can't consider Manchester United as favorites in this match.
Brighton were very good in friendly matches and beat Everton away quite easily, which is not such an easy task, yes there was a red card, but by that time Brighton were already winning 0-2 and most likely would have brought this match to victory.
And Manchester United beat Fulham with difficulty, and although they strengthened the team in the off-season I did not see anything outstanding in their game. I think that it will not be easy for them with Brighton, and I think that Brighton will not lose at home, that is, I would not risk betting against Brighton, but I also do not yet understand what to expect from Manchester United, how ready are they for games with strong opponents, will they focus on defense, will a draw in an away match be enough for them?