Currently, I don't think that Manchester United has more problems in their defense line, despite not having played many matches. Even from their last match, we saw how their defensive line was very active. However, it would be good if they could add more players to strengthen the defense, if possible.
Manchester United’s defense is not in a bad state that those positions needs urgent replacement of new players to strengthen those positions. I am more concerned about their attack because that is the position that they need to focus more on in order to be successful this season. Strengthening the attacking position is to me more important than focusing on the defense now.
As for predicting the favorite team to win the Europa League trophy, I don’t think our predictions make much sense right now because the competition hasn’t started yet. We need to see the teams' performances before making accurate predictions. There may be some teams that we wouldn’t consider top favorites for the Europa League trophy until the competition begins and their performances become evident. Last season, for instance, I don't think anyone anticipated Atalanta winning the Europa League trophy before the competition started.
Europa League in recent years have become a competition with a lot of competitive states in each round of the competition. It will be very hard to predict the potential winner now but base on past experience and how some teams performed in their respective league matches and made it here, we can get few teams that will have the strength and best chance to win the title, but anything can change at anytime when the league begins and we see the quality of each team.