for both teams, this fight will be very important. It's hard to predict in this fight. MU is now starting to improve, but sometimes they lose focus. Barcelona also had the same problem.
the match will certainly be interesting, a tactic war between Ten Hag and Xavi. if MU can break the domination of Barcelona's midfield control. it could be an opportunity for MU to get win. now MU has a line of defense and midfield that is quite tough.
I also think that this upcoming match in the Europa League is pretty important for both of the teams that are involved, even though Fc Barcelona and Manchester United are both very big clubs with a long and successful history and even though the Europa League basically is the cup of losers of all those teams that did not make it into the Champions League.
This time though i think the Europa League is pretty important for both clubs. FC Barcelona has huge debts and already needed to sell club property to not go bankrupt therefore every Million that can be won in the Europa League is very important to them. Manchester United on the other hand wants to prove that they have not only improved in the Premier League but that they can also keep up with very good teams on the international level again.