They will also definitely learn from their mistakes as to why they had difficulties when they were in the last 16 when they faced Qarabag. I am sure that Xabi is a coach who has good observations of their potential opponents this time. Xabi will also evaluate their weaknesses that their opponents can still exploit.
West Ham is an English league team that we know has a fast and aggressive style of play, Xabi must be able to minimize this by not giving West Ham the opportunity to develop their game. If this is done successfully by the Leverkusen players, I think they will be able to win both legs at once. However, this is just an analysis, of course it could be different when they play later.
Xabi Alonso has been quite successful in bringing many changes to Leverkusen and certainly we cannot deny if they are one of the challengers for the Europa League title this season with Milan and Liverpool, Alonso's ability to make Leverkusen a strong candidate for the championship cannot be separated from his expertise in concocting game strategies and also reading the opponent's current abilities, against Qarabag is actually a difficult match for Leverkusen especially they were close to it Defeated but the mentality possessed by Leverkusen allowed them to end the first leg match with scorer 2-2.
No different in the first leg, Leverkusen were also depressed in the second leg but lucky for them to get through the match with a victory, what you say is true because in some matches it seems that Leverkusen can make an extraordinary comeback and it happens not only once or twice in the league but repeatedly, Alonso's ability to raise the spirit of players deserves our thumbs up.
The match against Westham will be another difficult match for Leverkusen, although actually I really like Leverkusen but it looks like Westham will be able to make it difficult for Leverkusen in that match, currently Westham is quite impressive in the league and even they are able to slaughter other Bundesliga teams to reach the quarterfinals of the Europa League, although Leverkusen is indeed the favorite team but indeed Westham also deserves to be wary of.