Centre-back Stones, whose outstanding form saw him play back-to-back 90-minute games for England against Germany and Brazil earlier this month, faces six weeks out with the hamstring injury sustained in Saturday’s win at Leicester.
The return of captain Vincent Kompany at the weekend after his own lay-off is timely but, given the Belgian’s patchy fitness record, the Premier League leaders do appear short of defensive cover.
Nicolas Otamendi will return from suspension but the only other specialist options are the much-maligned Eliaquim Mangala and largely untried youngster Tosin Adarabioyo.
“We don’t have a big squad,” said City boss Guardiola ahead of tonight’s Champions League clash with Feyenoord. “To win the titles we need all the squad, especially important players like John and Vinny.
“On the other side, we have an opportunity. We have to play 12 games in a short space of time with only three central defenders. One of them is a risk, in Vincent only just back.
“It is not easy but I want to see how we react. Always when you are champions you have to handle the big situations, the tough situations.
“When everyone is ready and comfortable, that is not when you get credit. We are going to see how we react in the most important moment of the season. Until Watford, on January 2, it is about how we react.”
Mangala, who spent last season on loan at Valencia, looked set to leave the club in the summer but City’s failure to sign Jonny Evans from West Brom earned him a reprieve. He replaced Stones following his injury at the King Power Stadium. The 26-year-old, sitting alongside Guardiola at his press conference, said: “Football is like this. You have to be ready to take the opportunity. We need more than 11 players. Every player has to be ready to play.”
As well as weighing up the permutations, Guardiola admits deciding which of his lethal strikers, Sergio Aguero or Gabriel Jesus, should play is an even harder call.
He said: “Both with their different qualities and they deserve to play. They have a lot of games and they have to be ready and prepare well.”
Feyenoord boss Giovanni van Bronkhorst has no doubt City are one of the best teams in Europe.
“They have only drawn once, against Everton at home. All the other teams couldn’t cope with the level they have and the football they are showing.
“I don’t think you will find a person in this room, or Europe or the world even, to say that City are not one of the best teams at the moment.”