Another surprising thing is Stuttgart's performance, they were able to end up at number 2 and advance to the UCL. Guirassy is one of the players who has a good contribution with 28 goals in Bundesliga. But Guirassy is reportedly being wanted by Milan. Then Waldemar Anton, Hiroki Ito, Chris Fuehrich, and Angelo Stiller may leave. Because they have been key to Stuttgart's game this season and played very well. If they do go, it could reduce Stuttgart's ability to possibly not be able to compete if they do not take advantage of the transfer market to buy some players to repalace it.
After a team rises in the rankings, the value of the players in that team increases significantly. These players naturally transfer to bigger teams. But after these transfers, the team goes into decline again. Finishing in 2nd place last season was a great success.
If the players go to other teams, the efforts of the whole season will be in vain. However, if the team management makes a few new transfers and ensures that the quality of the team remains high, we can watch a very successful team in Europe next season
Currently, Bayer Leverkusen acts exactly in accordance with the policy you mentioned. They are trying to preserve the skeleton of the team and add important players. After the important player transfers, I am sure we will see a better Leverkusen next year. With Koç staying in the team, many players may choose to stay in the team despite receiving offers from big teams because they know that they owe this fame and success to Xabi.