Being in the Europa is different to the CL. It seems to take more out of teams. The travelling always seems more intense, perhaps the lack of top teams doesn't get the players pumped? Who knows, but playing Thursday & Sunday seems to be more of an issue than Saturday & wed in the CL.
I don't follow that, the idea that the Europa League is more demanding than the Champions League, or rather that if it is it's incredibly minor. Outwardly it's appears that the Europa League is more demanding because so many clubs seem to fall by the wayside when competing in it, but you've got to look at the clubs that it's affected, its your Spurs, Hulls, Fulhams, Wigans and Evertons, it's always clubs with smaller squads and smaller budgets, we aren't one of those clubs, we have been in the past (squad wise) when competing in the competition, but we aren't this season, our squad is massive.
Chelsea won the Europa League a few years back and it barely effected them, they still managed to come 3rd. Conversely Arsenal and us back in Rafa days were often badly affected by our Champions League exploits, but that had nothing to do with the competition, it was because we had very shallow squads (our 2005 squad was a joke). Point is, it's not the competition, it's the squad, and our squad is more than big enough to cope. I can understand why in 2013/14 people thought it was such a blessing not being in the competition, as our squad was paper thin, however today it is not, it's well fleshed out, and I'm looking forward to seeing us make use of it.
The only concession I'll add to this is that there's a higher number of Eastern European teams in the Europa League who are further away, so if the draw is unkind to you, it could have an effect, but it would still be pretty minor.