If referring to Man United poor performance in the EPL of course I agree but if you look at Man United performance in the Europa League then you will clearly be wrong in judging them. Amorim has said that he will focus on the Europa League for this season and the only ticket closer to being able to enter the UCL is by winning the Europa League championship. Let's see how this match will go because in terms of opportunities Bilbao playing at home is certainly advantageous but not entirely promising to win.
Manchester United's performance in the Premier League is very weak. However, it is true that this team has played quite well in the Europa League. Even then, I doubt whether Manchester United will be able to win against Athletic Bilbao.
Manchester United has faced Athletic Club in 3 matches before. Manchester United could not win in any of the 3 matches. However, these matches were many years ago. Now, maybe the scenario has changed. However, looking at Manchester United's overall performance, I do not think United will be able to defeat Athletic Club in the first leg match. Athletic Club's team is quite strong. Even this team can be put ahead of United.