Pique was in the squad list that Xavi brought to Mallorca, so I think Xavi can also give him a chance considering Araujo is currently injured. Crhistensen and Eric Garcia also seem ready and fit to play in defence against Mallorca, they were also in that match squad but all the decision rests with Xavi. So for this match I don't think Xavi will have a big problem as a result of Araujo's injury in defence, but because Barcelona have a very busy schedule in October I really feel Xavi has to be careful in choosing players in some easy match.
Araujo currently get injured with his national team seems he will absent several weeks later for Barcelona, exactly not really problem for Xavi Hernandez with Araujo absent because still have three central defender fit from Eric Garcia, Christensen and Xavi Hernandez have option give chance back to Pique after losing his regular position in this season. Gerrard Pique most fit defender I think because he not participant in national country and seem best option if Xavi want to used him against with Mallorca.
Lewandowski, Dembele and Raphinha are also available in this match, so I hope there are no problems with the strikers so I can expect Barcelona to win this match against Mallorca. But whatever the current state of Barcelona, we will see how they overcome this during October especially when they have to play some tough matches against Inter (2x), Real Madrid, and also Bayern Munich.
Although Lewandowski, Dembele and Raphinha available for this match against Real Mallorca I think risk when include them in starting eleven tonight because several days later have most important match for Barcelona against with Inter Milan in Champion League. Better left in the bench for Lewandowski and replace by Depay because with second player composition use tonight looks Barcelona easy to defeat Real Mallorca.