Rotations aren't critically necessary.
Only place I can see some changes is in midfield, not to rest but to give chance to potential XI players. Frenkie should be starting this one and Gavi to play more than before in second half.
Olmo also starter, either at AM or LW if one of the wingers show fatigue during week.
I doubt anyone is in need of rest after a week without game.
I would have Sociedad game as the only of these 3 with Gala XI.
Something like this
Espanyol
Peña
Kounde, Eric, Iñigo, Balde
Frenkie, Casado
Yamal, Olmo, Raphinha
Lewy
CL
Tek
Kounde, Cubarsi, Eric, Balde
Frenkie, Pedri
Y/R, Fermin, Olmo
Lewy
Then gala XI
Tek (but think Peña)
Kounde, Cub, Inigo, Balde
Pedri, Casad
Yamal, Olmo, Raphinha
Lewy