Leverkusen's performance has been phenomenal this season. They don't have a squad with star players but they managed to get an unbeaten record in the domestic league and almost became the first team in history to win the invisible treble. And it will be very difficult to repeat the same results next season. Leverkusen's defeat to Atalanta in the UEL final has exposed the weaknesses of Leverkusen's current game. To be honest, Alonso's tactics are really great but it seems like the players can't implement them fully. Correct me if I'm wrong. At that time Leverkusen often used tactics by placing many players on one side so that the opponent was really under pressure. But then Atalanta used high press man-to-man marking which made Leverkusen lose in the UEL final.
Yeah actually Bayer Leverkusen are lack of good squad and the star player, but with that they keep their performance very strong by keeping unforgeting record this season since they where able to maintain their position by remain unbeaten; which is terrible history by Leverkusen. Because this season has been so wonderful for them I'm having hope for them that next season they will perform more better and continue from where they stop this season to make sure they dominate Germany league.
Gian Piero Gasperini knows that Leverkusen does not have strong players one on one so this exposes Leverkusen's weaknesses. I think if Alonso manages to improve this aspect next season then Leverkusen might be able to shock Europe once again.
I'm very sure that Alonso will try as much as possible to fine solutions about the some players that are very weak in the team to sign new stars players which will make the the team so strong and become standard, because next season might tough them this season.