Even without Höjlund, Manchester United will win this match. I mean, if they want to be in the top four, they have to win. In recent games, even if they concede goals, they score a lot of goals and win. That's why defensive mistakes are not a big problem.
Hojlund's injury might affect Man United's performance. As we know, Hojlund has had quite an impressive performance recently and his instinct for scoring goals become sharp. So when Man United have to play without Hojlund it could be quite a tough battle for them. Man United does not have many options on the front line, so practically they will only rely on Rashford alone.