Zlatan Ibrahimovic's impact with the club made the team improve on the field and also mentally. His presence gives a boost to his teammates but it appears that the coaching staff will have to not rely on him for a longer time than expected.
According to what is reported by Il Corriere della Sera, there is a concern about the condition of Ibra's knee at AC Milan.
The recovery is not going really as planned. The times for it to heal could be lengthened especially if conservative therapy does not solve the issue. There is a risk of having a knee surgery.
The condition of the veteran striker of AC Milan, Ibrahimovic, has been discussed already by Vito Angelè in this article.