This season, Barcelona has had pretty good results in La-Liga, despite difficulties in European competition. However, MU position is worse, both in Europe and in the EPL (now look like better). This is then makes me believe if Barcelona has a better chance of winning than MU in the upcoming match. H2H is superior to Barcelona, but that's not what I see, but the current performance. However, an H2H that is not matched by the current good form will be history.
I don't think their head to head will be so important in this match, their head to head before was mostly in the champions league and European cup, they have never met in the Europa League before, this is the first time ever, so i am not going to use head to head to predict this game. I think United are going to win, Barcelona have a chance to win the La Liga, and that is what they would focus on, they would not mind being eliminated from the Europa League, but United do not really have the chance to win the premier league, so they may take the Europa League as a chance to win a trophy, so i think United would be more serious and they will win.