The Portuguese picked up a leg injury in the win over Red Star Belgrade in the Champions League and will be out for “a week to 10 days”, according to Pep Guardiola, joining Kevin De Bruyne and John Stones on the sidelines. Jeremy Doku could come in after an eye-catching start to life at the Etihad Stadium.
There is more positive news for Grealish and Mateo Kovacic, though. Grealish is back in training with the squad. Matheus Nunes keeps his place alongside Rodri.
Julian Alvarez starts after yet another superb display, in which he scored twice, again joined by Phil Foden and Erling Haaland.
Nathan Ake and Sergio Gomez started in midweek and are replaced by Josko Gvardiol and Manuel Akanji.
Confirmed team news
Manchester City XI: Ederson; Walker, Akanji, Dias, Gvardiol; Rodri, Nunes; Foden, Alvarez, Doku; Haaland
Subs: Phillips, Ake, Grealish, Ortega, Gomez, Carson, Bobb, Lewis.
Nottingham Forest XI: Turner, Boly, Niakhate, Mangala, Aurier, Sangare, Aina, Tavares, Dominguez, Gibbs-White, Awoniyi
Subs: Worrall, Kouyate, Wood, Hudson-Odoi, Elanga, Yates, Vlachodimos, Origi, Montiel
Doubts: Kovacic, Grealish
Out: Bernardo, Stones, De Bruyne
Time and date: 3pm, Saturday September 23, 2023
Venue: Etihad Stadium