Barcelona seem to be very lucky been grouped with Porto, Sharkhtar and Antwerp because clearly they are dominating in the group winning all three first legs and leading with nine points with Porto following behind with 6 points. It doesn’t look like Barcelona will lose even a game in this group, their future in the UCL this season looks very promising.
Even if they lose I don't think it will change anything in general, they can relax in some of the difficult periods and not really care about the group stage match. That doesn't sound like a good idea, but I don't know what will happen by then. The other question is what stage can they get to? Maybe they will fall out already in 1/8, what then?
To be honest, Barcelona does not have a strong enough squad to win the Champions League title. But the players in their squad are hardworking. Their coach Xavi is quite experienced. And Xavi's match strategy is also quite good. This is why the team has been able to maintain consistency in the Champions League. Moreover, the other teams in Barcelona's group are quite weak compared to Barcelona.
Barcelona will secure the round of 16 from the top of the table. And I don't think Barcelona will have too much trouble securing the quarter-finals. However, it will be very difficult for Barcelona to qualify for the semi-finals. Because every team that qualified for the quarter finals will be very strong. Barcelona are the most likely to be eliminated from the quarter-finals.