Unarguably,Xabi Alonso is the best coach of the season in the whole Europe as a whole,with the record he has set in the Bundesliga,it will be hard to be broken these days,and if they had extended that record to the last game,it would have really been a glory to Xabi and the club as a whole.Leverkusen shocked so many people this season,and with the way they play,they will be a big threat to big teams in the champions league next season when they will participate in the competition.I can't wait to see them play against teams like Arsenal,Barca,Madrid and Dortmund.
Maintaining performance will usually be much more difficult and it is their job to ensure they can maintain their performance like this season, or even better than this season. It is Xabi Alonso's job to ensure that his team can always be at a good level.
They are not like Bayern Munich for example who have stable finances, so they also have to think about not having financial problems in the end. Their players can actually create good chemistry, so it would be a good investment if they didn't sell the players who brought them to play like this season.
However, Xabi will discuss the team's needs again and he will propose players to bring in.