I don't see much chance for Barcelona to win the Champions League. Barcelona do not have the kind of wins and performances needed to win the Champions League trophy at the moment. When every position of a team is strong then good performance will come from that team but Barcelona is not strong in every position. Barcelona doesn't have a great finisher like Real Madrid, Barcelona doesn't have a good quality defender and Barcelona doesn't have a good quality midfielder, with so many weaknesses, it will definitely not be easy to do well in a tournament like the Champions League. Manchester City Real Madrid Bayern Munich are far behind in their preparations for the Champions League so this season is definitely going to be a tough season for Barcelona.
Barcelona is a mediocre club after Messi left, there's no chance anymore for Barcelona to win either Champions League or Europa League, the best they can get is domestic league or cheese burger league. Barcelona need to sell their club to rich owner first, then they can rebuilt their club and able to compete with the top clubs.
Barcelona need to be happy if they didn't get eliminated in the quarter final match.