Barcelona still hafta face a pretty tough remaining match towards the end of this season if we look at the opponents they have to face where there is still Girona although now Girona seems to lose its Magic but it will be inconvenient for them and it is the opposite of Madrid because apart from Barcelona at this time there are no other clubs that might be able to stem Madrid to win 3 points so in terms of opportunities it is clear that Madrid is still very favorite to remain champions this season .
Even though it's still possible, the chance for Barcelona to win the league is quite small. They have to win all of the remaining games including against Real Madrid to make their hope stay alive. If they don't win against Madrid, the chance will be completely over, and Madrid will be practically win the league. Slight advantage for Barca is that they can now focus on the league after being eliminated from Champions League, while Madrid will have to split their focus on the Champions League semi-final.
Despite having small chance, Barcelona should just fighting till the end with the hope of things will go in their favor. They should have mindset that the small chance can be gain, therefore they have to maintain their performance to keep the chance alive. This mentality is important for their squad as a lesson for their improvement in the future.