Don't see the problem with the back 4. Normally I'd say play walker at right back but surely it's clear how poor he has been this season. Stones may not have the legs to get up and down but he is better defensively. The other 3 at the back therefore pick themselves.
The midfield is about experience
..kdb has been off form but in big games he usually still has enough to turn it on. Rodri has to start...so the choice is either bernardo or gundo in midfield....he's gone for gundo for control but he has bernardo further forward where he is a goal threat.
Haaland is obvious.
The only other choice therefore is Grealish or Foden. Personally I think foden has been playing better from the right. I'm not Grealish's biggest fan by any stretch but he has earned his place at present....he does need to step up and add goals and assists but Pep is concerned, rightly do about transitions and he needs possession