Reduce 8 points in 9 matches when it comes to Real Madrid? This is impossible. Xavi will now try to focus all his attention on the Champions League matches with PSG, very soon they will have their first game in Paris, I assume that this is the only thing Xavi is thinking about now. Even if Girona overtakes them in La Liga again, this will not change anything since Barcelona is not fighting for the championship and, frankly speaking, they have no chance.
I would also think like you. I think Barcelona's current concentration is in the UCL league competition because there they have the opportunity to get a trophy this season even though it is tough but Barcelona can fight hard without depending on other teams to lose. It is very different from Laliga, even though they are focused and wipe out all the remaining matches, Barcelona still will not be able to win Laliga if Real Madrid continues to be consistent and it is unlikely that Real Madrid will make mistakes that will cause them to lose eight points. Maybe Xavi is aware of this, in the end concentrating on La Liga will be in vain, but for Barcelona who is in second place is still a priority. Moreover, currently Girona has lost concentration and has lost points several times, this makes it easier for Barcelona to maintain second place in Laliga.