Bayern Leverkusen may seem to be very optimistic in their title hopes this season but I see them dropping along the line because some of their key players may start dropping in their performance due to playing too many games both in the bundesliga and the European competition so when the players start getting tired and they don't have much solid substitute as compared to Bayern Munich who have great players as their substitutes. So the only thing that can assure them of winning the bundesliga this season is if they bring all their concentrations in the bundesliga and try to win as many matches as possible without losing or drawing any game.
Currently, Bayern Leverkusen will also continue to rotate players even though the quality of the players is not the same when facing weak teams in the Bundesliga in order to maintain the stamina of their key players when facing the strongest teams in the Bundesliga. Apart from that, Bayern Leverkusen itself is also struggling in the European League this season with the same consistency as in the Bundesliga so they need to implement player rotation to maintain their performance in these two different competitions.