Xabi Alonso is prominent enough to handle the hurdles which will be coming his way next season. Remember he's the main reason behind the sudden peak form of Bayer Leverkusen, they're able to comprehend the situations at hand and hitting top target in each season. Bayer Leverkusen have relaxed their players and they're warming up for the big season ahead. This is not an easy one because the entailed actions involves other oppositions.
I also have no doubts about the ability of Xabi Alonso especially for this season again because from what he has shown last season at Bayer Leverkusen to be able to win the Bundesliga is something extraordinary so that it has been a good achievement for him and hopefully can be achieved again this season. However, I do not think that Bayer Leverkusen can easily face the obstacles in the UCL, because it is a competition with quite high tension and very different from any competition including the Bundesliga.
There may not be easy matches like last year in the German league because most of the teams transferred a lot of players. The league became more difficult with the transferred players. For example, Borussia Dortmund's offensive line got much stronger. Bayern Munich also got stronger with good players. Kompany also made tactical changes. Bayer Leverkusen's squad from last year may be successful this year, but it may not be.
Well you may be right and you may be wrong on the other hand because it's true that their are more quality players that have been signed into most teams in the German bundesliga, like if you pay close attention to the signing made by Bayern Munich, you will definitely know that they really mean business and this season wouldn't be that easy for Bayern Leverkusen due to the fact that most teams this season no longer sees them as a small side, they now sees them as the champions, so every team in the league would want to give their very best against the champions, so I believe that it might be a lot difficult for Bayern Leverkusen than they expect.
But on the other hand, it might not be as difficult to them as we all are anticipating because if they can keep their key players of the team without them moving to another club, and their team spirit and togetherness is not tempered with, I believe that they definitely have all it takes to go hard on all their foes and be crown champions again if they can show enough consistency like they did last season, so it's a two way thing.