I think Man United is ready for the match against Sevilla, it will still be a tough game for them but most likely Man United has a bigger chance than Sevilla. In the previous two matches, Man United managed to beat 2 teams from Spain (Barcelona and Real Betis), so I think Man United is becoming more familiar with the style of football of Spanish teams.
I don't even think if sevilla is going to be even more tough opponent compared with betis. I just take the performance in the domestic league. Sevilla has horrible performances in the la liga. I see no chance for sevilla to win the match against manchester united. Betis can be destroyed by manchester united and sevilla will become even more easy for MU to beat it. Sevilla is not so stable as the club has been sacked sampaoli as a coach of club before. I don't even think the players can adapt as fast as possible to the new coach.
MU will have so many advantages over sevilla. Sevilla was not as strong as people called that as king of europa league. For me, sevilla is just an ordinary club in front of MU.
As you can see how inconsistent sevilla is at this moment. That proves that if this club is not in good condition when it will face MU as next opponent in europa league.