Manchester United's most recent match which was against Brentford has been postponed. And they have a home match in two days against Brighton now. Mata and Matic are still ill now but the condition of the rest of Manchester United's squad seems to be normal. And I don't see anyone who is ill in Brighton's squad. If it stays the same until the match, I don't expect the match to be postponed. Manchester United will have a tough match but they can continue winning I think.
Manchester United performance lately have been quite good. They won in their last 3 matches. And I think they should be able to win Brighton. Although, it won't be an easy winning for Manchester United. Brighton might not be a strong team, but they are known for drawing most of their matches. The Red Devil have to be well prepared, because winning the game will enable them slide up on the standings. They are currently 1 point behind West Ham.