Barcelona vs Real Sociedad on Saturday will be a tough match, because Real Sociedad will like to showcase some tactics that will make them shake Barcelona for the first half to make the match draw 0-0. No matter how prepared Real Sociedad prepare for this match, Barcelona will definitely use home advantage to embrace victory from this match, because Real Sociedad cannot stop Barcelona strikers not to have access to their goalpost through out the match. I believe, Barcelona will score two goals from this match that will make them to achieve the three points to celebrate.
Sociedad has impressive performance lately they even can able to beat Real Madrid last week but indeed it's really hard to beat Barcelona at Camp Nou but Sociedad should be keep winning to secure their place in the league standings from Villarreal but maybe because Barcelona have already win the title so win or lose it would not affect to their position and i assume they will do the same thing such as Napoli did last week in Serie A that Xavi will give an opportunity to Barcelona's reserve players to get more minutes to play and if this really happend i think there is a chance for Sociedad to win the match so we have to wait for Barcelona starting lineup before we decide to bets
To be honest, I don't dare to speculate too much for the match between Barcelona vs Real Sociedad. because, we do not have the latest information for both teams. although on paper, Barcelona is far in the favorites especially since the match was held at Camp Nou. plus, Barcelona has been confirmed to win the La Liga trophy, I'm not sure if Xavi will play his starting eleven. so, as you said. most likely, if Xavi will give the chance to some reserve players to get more playing minutes. however, it is possible that Lewandowski will still be made the main starter. at least, he still needs the coffers of goals to increase the distance from his competitors.
On the other hand, Real Sociedad need points to strengthen their ranking in the top four of La Liga standings. so, they will target full points against Barcelona. the problem is whether Xavi will play his core squad. if not, that means Real Sociedad has the potential to win the game over Barcelona.
To find out more, let's just wait for the two teams to meet.