Honestly, with the right tactics and a talented coach, it's not necessarily about signing new players. With their current squad, Barcelona can win a trophy. We've seen many teams perform well without having star players. For instance, we all witnessed Girona's performances last season. Even though they didn't win a trophy, they played impressively with average players. If Girona can perform like that, what's stopping Barcelona from doing even better next season with their squad? I can't easily conclude on Barcelona's performance now, but I believe they will perform well.
Yes it's really possible Barcelona will be able to win. A trophy with their current squad but it's under probability, infact they will literally struggle through it and may actually not be able to win it easily with their current squad, hopefully Flicks tactics and strategy turn out a salvaging one for them because they are definitely going to have some challenges getting the best this season, not when Madrid is present both in the champions league and the LA Liga. So far looking at what Flick is trying to do from their training news, there's hope for a massive improvement in the new season.