Barcelona will able to go to the play off easily without any problem since the club has porto as the strongest competitor in the group. The rest of the teams like shaktar or antwerp can be easily beaten by barcelona.
In my opinion if finishing at the first of second place will not that bad for barcelona but it's likely barcelona will be leading the competition in this group this time.
There are clubs that are not up to the standards of elite clubs in UCL. Barcelona thrashed Royal Antwerp 5 nil in the opening R1 of UEFA Champions League. Joao Felix is proven himself worthy of been in the starting XI for the blaugrana under Xavi Hernandez who's keen on developing the player into becoming one of the very best frontline in Camp Nou. Félix, Ferran Torres and Robert Lewandowski can work really good in league games, they're always on the good run up to achieved best results. Currently, Barcelona are topping the Group H after their spectacular game result.