At least in the group stage you can trust and let the newcomer prove himself, because Barcelona are not in the most difficult group, you can even experiment a little. Although there is also La Liga for that, so as not to take risks in such a tournament, especially for Barcelona this season it is very important. So far I see that Barcelona can definitely get out of the group, maybe even reach the quarter-finals, and then it all depends on the opponent
To qualify for the grub preliminary round, Barcelona will get a much lighter opponent, but to talk about experiments in the Champions League is very inappropriate even though later they will face a much easier club. I agree more if Xavi tries to give Lamine Yamal a chance in the domestic league because from there he can start to develop himself into a talented player in the future.
Basically, almost all groups look easy to become top of the standings for some of Europe's top teams, except for group F. Barcelona is fortunate to get relatively easier opponents this season, but I don't really dare to guarantee they can qualify easily and lead Group H in the end.
All teams can be surprised that Barcelona still has the possibility of failing to reach the last 16 if all the opposing teams are really able to make it difficult for Barcelona to win the match. I agree Barcelona are favorites in Group H, but that's not a guarantee to see them through easily to the next round.
For some teams group placement is very profitable for passing the group phase because they have superior qualities. But to guarantee qualifying as group winners is still quite difficult because they will compete with FC Porto and Shaktar Donetsk. These two teams cannot be considered weak in the group stage because they have proven they can pass the group stage several times. For one ticket they can definitely secure it, even if they don't win the group and I'm sure Xavi can get through that.
Group F is one of the most stressful because there are big teams and Newcastle United as a newcomer will definitely find it much more difficult. All teams still have a good chance of qualifying for the next round if they can perform all-out and balance the match. Can't wait to watch the matches, especially group F because this is one of the toughest groups this season in the Champions League, so the matches will be much more exciting and tense.