The 27-year-old has already missed two months this season after damaging ligaments in his right knee during training in August.
The first game De Bruyne will miss is Sunday's home game against Southampton. Asked if he was anxious about the injury, Guardiola said, "I don't know right now".
If confirmed, this will certainly rule De Bruyne out of next week's derby against Manchester United and as well as games against Southampton, Shakhtar Donetsk, West Ham, Lyon and Bournemouth. "We want him, but in the end, it doesn't depend on us". It's the desire of them, so we insist we want him.
"Playing in the top teams is not easy for young players, but he showed his qualities again". But his agent, and him, finally decides. According to reports in England, Brahim could join Real Madrid for free next summer as his contract is up. After several years with City, the player made a decision to stay with the English club at the start of this season but opportunities have proved few and far between and that could force him to seek playing time elsewhere.
"Yesterday he came back in many, many things".
"Today he was involved in offense and defence, hopefully what happened in the last minute is not serious".
City must wait to find out their quarter-final opponents after Leicester's game with Southampton on Tuesday was postponed following the death of the club's owner Vichai Srivaddhanaprabha in a helicopter crash outside the King Power Stadium on October 27.