Liverpool strength is not new and the team has been elite for a long while too; they just had an injury ravaged season inn the previous campaign which derailed their performance and forced them down only to Europa league spot in the previous campaign. Can Liverpool push for the Europa league title and top 4 simultaneously? Time will tell
In any case, Jurgen Klopp is doing some rotation of the squad, releasing not the first version in the first half of the match. I think that even with such experiments, Liverpool should calmly leave the group in the Europa League, but there a lot will depend on the playoff grid. In addition to the obvious Bayer Leverkusen in the Europa League, let's not forget about the clubs that finished third in the Champions League and who will go down to the tournament. There can be very strong and status clubs there. Yes, and the same Sevilla may well take third place in its group and find itself back in its favorite tournament, immediately closing the question of the UEFA Cup winner for the rest of the teams 
Liverpool is still having salah who has been recording a new record in EPL. I do know that we may see some clubs were going down caused by they could not go through group stage but im not even worrying about that caused by liverpool's UCL standard.
There's no problem in facing UCL team on europa league. The most easiest way to secure europa trophy and get UCL spot instantly rather than competing in EPL to get it.
I have faith in liverpool now.