Sounds like Gabi and Saka should be fine for this so no real movement in terms of team news. Brentford have a whole host of players out in defence but they did get a draw vs Chelsea and took City to the wire so can't be taken too lightly. With that in mind I'd personally be happy with just the 3-0 win.
I wouldn't mess with the lineup too much. Maybe give Martinelli a bit more time with his cut and bring in either Jesus or Trossard. I'd stick with Jorhinho at the base personally. Partey looked too rusty to risk starting him. We've had a bunch of breaks, 'easy' games where we've been able to make early subs and have another 3 week break after Porto, so I wouldn't worry too much about asking the players to go full on twice in one week.
Lets do the business and enjoy watching Liverpool and City cut each other up.