That left Stones and Nicolas Otamendi as City's only senior centre-backs and the pair looked shaky last time out as City went down to their first Premier League defeat since January, losing 3-2 away to promoted Norwich City.
City will be further stretched for the upcoming period after Guardiola told reporters ahead of a Champions League trip to Shakhtar Donetsk that Stones was injured in training on Tuesday.
"A month, four or five weeks," Guardiola said when asked how long Stones would be out.
PEP: @PhilFoden is a virus problem with his stomach and not able for this game, I think (he will be back) for the next one.— Manchester City (@ManCity) September 17, 2019
John Stones got injured this morning. The Problem is muscular... 4-5 weeks.