Barcelona have 2 games in hand so at best they can reduce the gap to 10 points between them and Real Madrid so yeah they still can do it now that I look again at the table. Real Madrid drops 10 points and they still are in game but also Barca has to maintain a flawless run and this is what makes it difficult.
I have my doubts about Barcelona, of course because they are very unstable in many games. I don't think their win vs Atletico Madrid is the start of their comeback this season to continue competing until the end of the season, but it's good if they can maintain their form.
Espanyol is not an easy opponent for Barcelona and I think it will be a difficult game to predict. If Barcelona win then they can get back to 4th place again today by shifting Atletico Madrid to 5th place. But there are doubts about their chances of winning, I think today's result will be a draw.