I don't think the board of borrusia Dortmund did made a mistake, it's been in their policy the trade of players be it their star or not, they make good profit of it and at same time are able to breed new set of players that still helps them stay a float such that they always maintain decent stance in the table most often than others does. What I see is happening at this time is the change in the era and breed of players such that what was applicable before may be fading away except if some adjustments are made to get it suiting into the new era least they get the team setting back with their performance and results.
This format of building and selling of player by Borussia Dortmund is not that bad though, if that’s what actually works for them, they will continue doing it and I don’t think they’ve thought of changing that policy recently. They still lack that vision of being champions no matter how they try and go far in all competitions maybe they should also work on that and not only focus on making money from young player that they sell. Times are really changing and maybe this format may not be good for them again, so they should also look for another means to continue being amongst the best team and also improve their finances also.
I also can't wait to see how Leverkusen will perform in the Champions League this season apart from their performance in the Bundesliga this season. Because Xabi Alonso will definitely try to maintain his good performance again this season even though this may still be doubted by some people because the Champions League competition is a competition full of pressure. And also next season Bayern Munich as their strongest rival has made several changes that may affect their strength in the Bundesliga and also the Champions League.
The performance of Bayern Leverkusen last season have made a lot of people to wonder how their performance in the champions league will be next season, if they can still stand a chance there as they did in the Bundesliga or not. The competition is highly more competitive here and will require that Bayern Leverkusen give more than what they actually had in the last season in their Bundesliga and Europa League participation. They are a team that if they want to stay at the top, they’ve to be consistent in their performance and be at the top in both competitions. Xabi Alonso knows much is expected from him, so he should be prepared to give that much in the upcoming season games.