Juventus must have seen who their opponents were in the semifinals of the Europa League and Juventus have also never underestimated any opponent they have faced so far. And of course Juventus will be very careful with Sevilla because every team that has entered the semifinals in a competition like the Europa League must be considered good because each of them certainly has advantages. So you should be careful and there is no reason to underestimate it.
The two teams and their respective coaches still have time to find a good solution in preparation for the first leg in mid-May, but I think both of them have a chance. I don't know how many people favor Sevilla to win and qualify for the final, but I think this semi-final will be highly anticipated especially after Sevilla managed to beat one of the favourites.
At the moment I think Sevilla is very worthy to be expected to surprise in the Europa League. Sevilla managed to come back from a slump towards the end of the season so they have had good form in the last few games. They won several tough matches including two tough matches in La Liga which they won in a row. Meanwhile for Juventus, they had to swallow 3 painful defeats in 3 consecutive matches.