I still think Barcelona has a slight advantage maybe 55-60% to win against Manchester United that either 40-45% to win.
I don't think Barcelona will care if they are eliminated by United, they will surely want to win but their focus is on the La Liga, they are top of the La Liga and they just beat real madrid to win the Supercopa, so if they didn't believe before, now they believe that they can win the La Liga from real madrid, and that is the big trophy they want. If the Europa league would be a distraction to them if they go far in it, then it is better they are eliminated by United early. Manchester United have been playing well in the premier league too, but they are not the favorites for it, but in the La Liga barcelona are favorites.
I will reiterate. Xavi once said that after Barcelona were knocked out of the Champions League, he said on several occasions that Barcelona was targeting two trophies at once, namely the Europa League and La Liga. that way, Barcelona will not underestimate their opponents in the Europa League.
IMO, when referring to last night's match when Barcelona against Real Madrid. Their playing pattern is very different from before, now Barcelona's defense is more solid, their midfielders are starting to be productive, especially the presence of De Jong makes some differences plus Xavi dares to experiment with his new formation. I like watching Barcelona play against Real Madrid last night, even though it's not a prestigious event. however, the El Clasico match is a battle of prestige from the two Spanish giants. plus points for Xavi, and winning the Supercopa.
In the playoffs later, I'm sure the Barcelona vs Manchester United match will be a very exciting match for us to watch.