Barcelona has home advantage and indeed they are the favorites, even the percentages in several places give them an advantage in Barcelona victory, but Girona needs this win to be able to regain first place which has been taken over by Real Madrid.
I sure that even though Barcelona has the home advantage, Girona will play very well for the full points they can get because if this ends in defeat then in the future Real Madrid will have the advantage in getting points.
Girona is only competitor for Real Madrid to get the title this season and this is quite difficult competition for Girona because Real Madrid is the king of La Liga.
Barcelona won 7 of 8 home matches in La Liga this season and they have quit well performance when playing in front of their fans, just got one loss on El Clasico match from Real Madrid as their home match. Actually with impressive performance from Girona and success on the second standings position seems Barcelona keep favorite team for winning when playing on their home. Last home match against top third teams standing Atletico Madrid, Barcelona have dominance and keep controlling the games play against Atletico Madrid although winning least one goal.
Girona won't loss points yet because keep compete on the top place and have difference many points from Barcelona, its excited match between 2nd and 3rd standings position although Girona loss their position not drop yet to 3rd place.