Did you watch the Spanish Super Cup final which Barcelona just won. Barcelona played like crazy to win trophies, the struggles of Barcelona players were not in vain, they managed to beat Real Madrid with a landslide score.
Let's compare the Super Cup competition with the Europa League, it's impossible that Barcelona don't care about the Europa League trophy. The Europa League competition is more prestigious, of course Xavi will prioritize the Europa League this season, especially since Barcelona failed in the final last season.
I'm sure Xavi's priority right now will be La Liga, especially since after beating Real Madrid they will have enough self-confidence to keep their lead. Barcelona won't mind winning the EL as well, but the first game will be against the MU, who are also in great shape right now and they beat City this weekend. We can say that both clubs are close to their optimal form, it should be a very interesting confrontation.