The England defender was withdrawn at half-time of Sunday’s 6-3 Manchester derby thrashing of United at the Etihad with a muscular problem and was not involved in training, meaning he is sidelined for the visit of Danish opposition in Europe.
Midfielder Rodri returns to bench against Copenhagen, but Walker’s Three Lions team-mates John Stones and Kalvin Phillips are both still out.
“We will train this afternoon and we will know exactly,” Pep Guardiola said of the latest City team news at his pre-match press conference on Tuesday.
“Rodri feels better, but Kyle, I think is out. But we have training later.”
Asked if Phillips could be available before the World Cup, Guardiola added: “I hope so. I hope for him and the national team. But I am not a physio – the doctor told me he is doing good.”
Ruben Dias was only fit enough for the bench against United but starts here alongside Aymeric Laporte after he played his first few minutes of the season after knee surgery over the course of the summe.
Given City’s strong position in Group G, rotation could be in order, particularly with a trip to Liverpool in the Premier League looming.
Guardiola has already confirmed Erling Haaland will need to be rested at times but resisted it tonight.
Man City starting XI vs FC Copenhagen (4-3-3): Ederson; Cancelo, Dias, Laporte, Gomez; Gundogan, Grealish, Silva; Mahrez, Alvarez, Haaland