Manchester United barely beat Lyon in 120 minutes and were matched with Atletico Bilbao in the semi-finals. Atletico Bilbao is a team that comes after Real Madrid, Barcelona and Atletico Madrid in the league and is a very difficult team compared to Manchester United. United, who are in 14th place in the Premier League, are experiencing inconsistency in their home performances. Considering their inability to maintain their 2-0 lead in the Lyon match and their weaknesses in defense, it is very difficult for them to get past Atletico Bilbao. Athletic, who are already in the Champions League pot in La Liga, will be comfortable here and will rest their good players and come out on the field fresh.
That's all true. Man United are having one of the worst seasons in recent years, when it comes to the league position. It looked for a moment that their new manager, Ruben Amorim could turn things around, but the signs of improved performance were short-lasting. United haven't won any of their last 5 Premier League games.
Athletic Bilbao currently occupies high 4th place in La Liga, but there's a big gap between them and Real or Barcelona (12 and 16 points respectively), so they're not quite on the same level as the top 2.
Despite their poor recent performance, Man United are still a slight favourite to qualify to the final, with odds of x1.84 (Bilbao: x1.93). That's probably because the Premier League is ranked higher than La Liga, and because of the fact that, after a failed Premier League season, United will be extra motivated to focus on the Europa League.
Also, United's main problem is inconsistency, but they have a decent squad, and if they play at their 100%, they can put up a good fight even against the top teams.