Guardiola has been confirmed as Bayern coach for next season.
German legend Schuster remarked: "What I see ahead for Guardiola is difficulties. They have a sporting director, Matthias Sammer, Karl Heinz Rummenigge and Uli Hoeness. He will be fighting them all.
"And these ... yes it's complicated. And these people will also have their opinions."
Though Schuster added: "Bayern demands much, but also take good care of their players and their coaches."