Ever since Leverkusen lost in the Europa League final, they have been constantly conceding a lot of goals and that is not a good sign. Most teams that become champions do so because they have a good defense, and at the end of the league they have not conceded more than 25 goals. In many cases they even end up conceding less than 10 goals. But look at Leverkusen:
1 - In all the friendly matches they have conceded a goal
2 - They have played 2 games in the Bundesliga, conceding at least 2 goals in each game
3 - They have only signed 1 defender this season: Jeanuël Belocian
https://www.transfermarkt.pt/bayer-04-leverkusen/startseite/verein/15In just 2 games they conceded 5 goals. This number of goals conceded should be at least 10 or 15 games, normally for a team that is a candidate for the title. By this I mean that the Leverkusen coach has reason to be worried, because it is possible that they will not even finish in the 3rd position. This weak defense will also be a problem in European competitions.
Not expecting much from Leverkusen this season honestly. After a belter of a season, a quite unbelievable one, you start over-complicating things. That's what's going on over there right now, and it's not their fault. I understand that they have built a certain expectation around them, but always living up to the expectations is difficult, for everyone.
Leverkusen already had tough games in front of them, and are having a hard time keeping up. They still would be a top team and would stay top 4 in the league till the season ends, but they don't have all that it takes to go for the title again. A few offloads and incomings probably in the winter, but that does not really change much, does it? They needed to strengthen a lot more in areas they need strengthening because even after an unworldly season of football, there would be areas you need upgrades in, but I don't think Leverkusen were able to get that upgrade.
Now they are also going to be playing UCL in a few weeks, and there is always a flow of league matches around them. So it will be really interesting to see how they cope up with that, or were they only a one season wonder? because more often than not, teams who get crazy success in a season, struggle really hard to keep up with that level of consistency. So this will be the real challenge for Leverkusen, which I am really excited to find out.