The fact that the match will be played in Spain and Manchester United's recent poor performance make Athletic Bilbao the natural favorite. I think Athletic Bilbao is the team that can win this match. However, Manchester United, whose only way to qualify for the Champions League is to win the Europa League, may have come to this match very well prepared. If their goalkeeper Onana does not make an absurd mistake, they may have a chance to win the match.
It is difficult to choose a favorite team in this match. Manchester United has been in a bad shape all season. Manchester United's performance in the Premier League is very weak. However, Manchester United's players are able to perform quite well in the Europa League platform. United has qualified for the semi-finals by defeating strong teams like Lyon and Real Sociedad.
Athletic Bilbao is a strong team. Bilbao has the ability to win against Manchester United. Even then, I cannot say for sure that Bilbao will win. Also, considering the home match, I cannot consider Bilbao as a favorite. The match will undoubtedly be very competitive.