Qarabag is not at Leverkusen's current level, but looking at the statistics, this team has high fighting power in every match. Yes, even though we know that maybe the winner is Leverkusen, we need to watch this match to see how well Qarabag can withstand Leverkusen's attack. Moreover, currently Leverkusen is unbeaten in the domestic league or UEFA League. I don't think Xabi will underestimate all teams from any continent because if they make a blunder they will be slapped by teams at Qarabag's level.
I think Qarabag might not be as good as Leverkusen right now. But we should remember that numbers don't always show everything. Every game can have surprises. Qarabag works hard and never gives up so they can still do well.
Leverkusen is expected to win, but it's important to see how Qarabag plays and if they can surprise everyone. Leverkusen hasn't lost any games in their league or UEFA League which is good but it doesn't mean they will win every time. There can be a team which can come up and can defeat Leverkusen.
I believe that Leverkusen will be able to play well in the first leg match against Qarabag and this can be guaranteed that Leverkusen will have the aggregate advantage to be able to win and qualify for the next round.
Moreover, they have previously met in two matches and all of them were won by Leverkusen. In the next two matches, I am also sure that Leverkusen can be like before, winning two matches at once.
Maybe Qarabag could have chance to win but that will only happen if they are lucky by having an unexpected surprise, it just that the chance of that happening is very small.
Xabi will prioritize all his players to be able to play at full strength to be able to maintain an immediate advantage in the first leg match.
Leverkusen is one of the strong candidates in the Europa League competition this season and they will really fight for this opportunity as best they can.
Moreover, in the group phase Leverkusen were also an unbeatable team, they really were team that could never have been imagined like this.