Juventus is not in good performance in Italian league, but in Europa league Juventus is focusing in Europa league, Juventus had serious challenge in their performance in Italian League in the early time of the season. Juventus are currently in their best form and this could be a hindrance for the Mendilibar squad if they don't implement a good strategy to be able to bring Juventus home. Juventus have two targets this season, namely winning the Europa league and securing a Champions League slot next season.
I think Sevilla are a good match for Juventus, If Manchester United had beaten Sevilla they wouldn't pose much of a threat to Juventus as much as Sevilla would and since they have a good record competing in this competition they will have some advantage, they have done it in the past we shall see if they can do again this time.
If Juventus can win the Europa League title this season, then Juventus will not have to work hard to secure a Champions League ticket in the Serie A standings. Because, if Juventus win the Europa League title, Juventus will automatically get a place in the Champions League next season. But yes, apart from that Juventus does look more focused on the Europa League, moreover the opponent is Sevilla which I think of course Sevilla has good capabilities in the Europa League.
Therefore, Juventus faces a difficult challenge at this moment, because a team on the rise like Manchester United has also failed to beat Sevilla. So yes, I'm sure Juventus will still not be easy to beat Sevilla, but for Sevilla it looks like they have good luck in the Europa League so any result can still happen in this match.
You are right but I think Juventus will try hard for both Serie A and Europa League because they know Europa League a very risky and even a team like Manchester United can lose everything in a few minutes while they were the first hope for the Europa League title I guess Juventus will have a hard day against Sevilla because they are very much unpredictable in Europa league.