De Bruyne facing 'three or four' months out, says Guardiola
De Bruyne limped off early in City's 3-0 win over Burnley to open the Premier League season on Friday.
The 32-year-old had suffered a similar injury in the Champions League final just over two months ago as City beat Inter Milan to become European champions for the first time.
"It's a serious injury," said Guardiola ahead of the UEFA Super Cup between City and Sevilla in Athens. "We have to decide surgery or not surgery."
He added: "Surgery I think will be three or four months out."
City have already lost two of their most potent attacking players from last season as Ilkay Gundogan joined Barcelona and Riyad Mahrez departed for Saudi club Al-Ahli.
And Guardiola said De Bruyne is "irreplaceable" despite having the likes of Phil Foden and Julian Alvarez to call upon to deputise.
"Kevin has specific qualities. To lose it for a long time is really tough for us.
"At the same time we have to look forward. The skills for Kevin is irreplaceable but we have players with different talent."
