Barcelona vs Manchester United match has now become the main object of Europa League discussion. But I still have little fear for clubs like PSV, Roma, bayern leverkusen, midtjylland and Monaco. This clubs are doing well in their league but their chances of winning their league is much quite narrow compared to their chances of winning the Europa League, for that they might show much more curiosity in winning Europa league matches than clubs like Barcelona and Arsenal. Therefore one should not underrate them in Europa league matches.
I think that just because barcelona and arsenal have big name and then you will be underestimated another club like think barcelona will be winning europa league easily. don't you remember once barcelona has also become favourite team last season but frankfurt was beating it easily?
I think that even arsenal didn't have big chance to win this trophy easily. The arsenal was not capable to win caused by there are so many underrated team play in europa league. PSV was doing very well in the domestic league.