Xavi Hernandez would encourage his new young players to suit up for the main squad, because it's time to elevate the team to the next level, no longer counting on the primary players, but rather sticking to future plans, which are the young players who are eager to start for the team, which might crumble currently, but they will definitely become stronger in games. I doubt Barcelona will reach a vital stage in the UEFA Champions League this season because they are woefully underperforming in La Liga but are yet to show any signs in UCL competition.
I hope you do remember how Barcelona turned into flash in a twinkle of an eye during second leg in Laliga, and that was when Real Madrid start to skip wins in their matches. 4 points differences in a domestic league is too fresh to start to think they will not go far. However, the UEFA stage is excellent condition, having played 3 matches without with 3 wins is something to be happy about, I don't think they will have any problem here perhaps maybe after this point and if they are lucky the way the group stage was easy, it is going to be another inducement to further to Semi final.
Several teams that have consistently won in the last 3 Champions League matches are Bayern Munich, Real Madrid, Manchester City and Barcelona. I think these four teams will only need 2 more wins to maintain their chances of safely qualifying for the next round and I think it will be quite easy for them. For Bayern Munich and Real Madrid, perhaps they are in a quite difficult group because Manchester United and Napoli are predicted to disrupt their chances, but it seems that is no longer a problem. On the other hand, Manchester City and Barcelona are in a group filled mostly with weak teams and I think it will be easier for both of them to secure points in the next match without any problems.
Going further, Barcelona don't have any business in group stage, too real to further into group of 16, Real Madrid will go for sure even with Napoli because out of that 4 teams in their group stage, they are the only attested teams that will move out of the stage, the remaining two will go home, one to Europa while the other one will go home to rest and try again next year.
Watching Elclasico yesterday, it embossed my confidence in Real Madrid to win this season Champions League, we now have another Haaland of last year among us and that's like the only guy that is pumping Real Madrid to win this league this season, even Haaland of Manchester City doesn't comes close to what he is doing right now.