Barcelona team is currently performing one of the best. The coach of the team is Xavi, who has brought the team to this stage with one of the talents. Manchester United is a strong team though. However, Barcelona's current performances certainly qualify them to beat Manchester United.
It is not enough and I explained below. But by combining many factors including history, I think Barcelona will have better chance to be a winner against Manchester United finally.
How does Barca current form gives them an advantage edge against Manchester United? I think both teams look well to balance just like the how both teams where when they meet in the 2009 Champions league. Both have a brilliant and exciting coaches. The most interesting thing with this encounter is the fact that both clubs have made their respective home as fortresses and this encounter will surely be won by the team that takes a point or more in the opposition home
About player quality, I believe Barcelona are better than Manchester United a little bit. About whole results of them so far in this season, Barcelona are better a little bit. About their latest forms, I also see Barcelona are better a little bit because Manchester United just have a little decreasing performance last two weeks.
If you say it is enough to conclude that Barcelona will win against Manchester United, I disagree because I think all of these are not enough. If Manchester United could make us surprised by beating Manchester City in Premier League, they can beat Barcelona in Europa League.
The another minus point against Manchester United is they have very bad history when playing against Barcelona. You must take it into consideration for their coming matches.