If they succeed in maintaining their performance, then I am sure they will be able to talk a lot in the Champions League next season.
Maintaining a performance like last season is not an easy task even though Xabi has very reliable intelligence but to be honest I doubt it and my reasons are quite clear if experience really is the main role in competing in the UCL and Leverkusen does not have that much experience in the UCL.
My doubts became bigger when Leverkusen failed in the final round of the European League looking very unprepared and that means Leverkusen will still have difficulty competing in the UCL which is filled with the strongest teams in Europe.
I think they can do that, especially since they have retained many of the players who are in the squad this season.
Not sure whether Leverkusen can retain some of its important players because Wirtz, a highly prioritized midfielder, has recently been linked with other teams and this could happen because the season break is still very long and something could happen.
I feel that Xabi can also know his players' abilities well, so that will help him to be able to apply the right strategy so that the players he has can show their best abilities in the game.
Previously, I also said here that there is no doubt that Alonso can quickly become close to all Leverkusen players and can create perfect performances in every match and can even appear unbeatable in the Bundesliga.
But the problem is about the UCL and Alonso will not easily provide the right strategy because player readiness is also really needed.