I agree with you that Barcelona cannot catch up with Real Madrid at the top of the La Liga table. Real Madrid is leading Barcelona with 8 points, and it will be hard to drop points that will make Barcelona equal or overtake them at the top of the La Liga table.
Actually it could be Barcelona if they are able to play consistently in the next match, but Real Madrid is too strong to expect them to be weak, because they continue to win and draw as if Real Madrid doesn't want to experience defeat in all their matches so it is natural that Barcelona will have difficulty to catch up with Real Madrid's current position, because we can see that Girona was unable to avoid Real Madrid's shadow and in the end Girona fell and ended up in third place in the current La Liga standings.