Barcelona needs to try their best in order for them to win Osasuna, otherwise, they'll have to fight till the end of the season on pressure to make sure Madrid does not take over them. I feel this is the best opportunity for Barcelona to widen the point gap, because we don't know the unforeseen challenges that might come up in future before the end of the season. It's an important match for Barcelona.
First of all, Barcelona will have to continue their winning streak if they want to keep the top spot in the points table. If they cannot win consistently, it is not possible for Barcelona to keep the top spot in the table.
If they win against Osasuna, Barcelona will be ahead of Real Madrid by 3 points. The match is very important for Barcelona. The bigger problem is that Barcelona lost 4-2 in the last match against Osasuna. This is probably Barcelona's biggest defeat this season. Hansi Flick is looking forward to revenge. It seems that Barcelona's players will play very aggressively in the match.