Barcelona's opportunities for winning La Liga still open yet, if can make reduce 5 points remaining by defeating Real Madrid on game week 32 and wish on 6 matches left Madrid loss their points. All possibility is open with Madrid or Barcelona will be the La Liga winner candidate in this season although Madrid has large percentage become the winner.
And recently Barcelona's performance has improved quite a lot, different from them at the start of the season and several previous meetings this season, so I think that the El Clasico at the end of April will be quite fierce compared to the previous El Clasico matches this season.
The 8 point difference in the current standings is also a big motivation for Barcelona because if Barcelona manages to win the match then they have hope of still being able to compete in the race for the La Liga title this season.
At least, considering the situation and or the results of the matches they got in the Champions League, it is likely that Real Madrid will spend more energy later. But about Barcelona, on the other hand, will probably be able to save energy and will certainly have better preparation than Real Madrid, who still have to make greater efforts in the Champions League against Manchester City. With considerations like that, at least at this moment Barcelona will have a good chance not to lose against Real Madrid in the El Casico match later. But yes, because of course in this el clasico match has high prestige, Real Madrid will also continue to strive to play well and therefore, at least Real Madrid and Barcelona both have a chance to get good results in this el clasico match.