Many predict that Bayer Leverkusen will be the center of attention in the next Champions League and want to see how Xabi Alonso competes with many outstanding coaches who have experience in the Champions League, but we cannot guarantee to what extent Leverkusen can survive in the Champions League despite the previous unbeaten achievements, it is possible but it may not be what we imagine or go the other way and cannot survive even in the group qualification.
But it is interesting how far Xabi Alonso will take Bayer Leverkusen, whether it will reach the final like Dortmund or not.
Looking consistent performance of Bayern Leverkusen in this season make them become high intention team for next season will appearance in Champion League has potential make unbeaten record after invisible winning Bundesliga this season. Actually drastically difference level between Europe League and Champion League although Bayern Leverkusen only got one loss in Europe League can't guarantee easily in Champion League winning every matches because get many difficult team since phase round exactly after UEFA adopting new format and each team will play 8 matches on phase group.
I can't speculate too far with Bayern Leverkusen performance in Champion League next season, although most of their old player defend and recently Xabi Alonso sign some top players but need more consistent performance when playing in higher level competition such as Champion League.