Betis are in fine form so in no way will this be an easy game. But if we are to rotate we need to do it in the league.
Think we can easily rotate 4-5 players and be competitive.
Cubarsi-Eric-Inigo-Araujo, any combination should be enough in Liga.
Balde-Martin, Gerard can suffice in most games
Kounde doesn't rotate.
Frenkie-Gavi-Pedri-Eric, at least one of Frenkie or Pedri needs to play to keep level high.
Fermin-Gavi-Ferran, this spot is open after Olmo's injury, will probably differ from game to game.
Raphinha-Ferran, either works as Raphinha is out of form anyway
Yamal doesn't rotate, otherwise Ferran or Raphinha can play here.
Lewy-Ferran, both are in great form and can play 60-30 each.
For Betis I'd go
Kounde, Araujo, Inigo/Pau, Martin
Eric, Pedri
Ferran, Gavi, Raphinha
Lewy
I don't think Yamal will be rested however, at most subbed late in second half.
Go for Pedri-Frenkie switch at HT if things are going well.