They are leading the laliga and if they are putting much effort to any of the league should be laliga. Barcelona target is not winning the europa. Real Madrid has been winning laliga, Barcelona feels it is their turn to win the league this season.
Barcelona can do that but it must be even more consistent compared with real madrid. Barcelona has only a very small point gap to the real madrid. Real madrid can surpass it anytime. Barcelona will have a hard time to win the two title for this season. THere's no guarantee barcelona can win la liga too.
Barcelona didn't have big gap with real madrid even leading the la liga will still give some worries about real madrid to be able to reach or even surpass barcelona. Barcelona may not able to win against manchester united. It seems like that MU is far stronger than before.
Their main striker which is Lewandowski will be absent in their coming match. Lewandowski has been generating goals for Barcelona this season, his absence may cause Barcelona to drop in performance.