You cannot be counting Barcelona as favourites to win the Europa League when they have not overcome Manchester United that is a big challenge for them. If you want to count favourites, it will.be fine you mention both of them because anyone that won between Manchester United and Barcelona may likely get to the finals of the Europa League for this season. It is unfortunate that the two big teams met early
Barcelona still not yet in the favorite for UEFA Europe League trophy because they have heavy match against Manchester United at play off round, current bad performance facing with bigger team I doubt chance for Barcelona can win against with Manchester United and not really sure with Barcelona chance can lead to next round.
Early have to see big match at Europe League between Barcelona vs Manchester United because I think excited if both team meet at final stage than play off round, but still have many big top teams left on Europe League from Juventus, Arsenal and the historical team with EUFA Europe League trophies Sevilla.