Barcelona has some missing players, so this could be a little bit difficult for them to handle, I am not entirely sure if we are going to see them do this greatly, we are going to end up with some issues on the long run if we are looking into this.
I agree things aren't going to be too great, we are going to end up with a much better result when the time comes, but right now these injuries and the fatigue of most players will play a big role. Don't forget, this is Barcelona, they have many national players, so fatigue plays a role.
Both will have league game too before this one right? So that means we are going to see how teams come back when the time comes, this way we are going to end up seeing what both teams look like before we get to bet on the game. I understand it may look like we are going to end up with a much better result, but at the end of the day we are going to end up with a much harder situation for all of these situations at hand.
The missing players aka injury players
are no issue for Barcelona imo, they played fine and exceptionally without those players though with their presence there could be more performance from them maybe... but the fact that everything seem smooth though i don't seem to see any form of fatigue at the moment(at least before the nations game), without their presence shows their current capability.
At the same time I might want to agree with waiting to see their return before any form of betting, it's actually a good idea and I believe both team will have sigle domestic match before playing eachother in UCL the game before could be use for the prediction.