Manchester City captain Vincent Kompany is out for a month with a groin injury, manager Manuel Pellegrini has said.
Kompany came off in City's Barclays Premier League victory against Newcastle on Monday night after 71 minutes.
The Belgian's unavailability will fill supporters with anxiety, since Kompany's absences through suspension and injury in recent seasons have coincided with slumps in form for the Citizens.
When the 27-year-old was injured at Stoke City in the FA Cup last season, City trailed league leaders Manchester United by five points. When he returned, the chasm had widened to 15.
Pellegrini said: "I prefer the doctor to say the last word, but I think (he will be out for) at least one month. The doctor can give more information."
Kompany will miss City's trip to Cardiff on Sunday and home game with Hull City next week.
The international break could allow him to recover in time for City's visit to Stoke on 14 September before the first Manchester derby of the season eight days later.
Kompany's lay-off will intensify City's search for a new centre-back. Matija Nastasić, who suffered an ankle injury last month, could be fit to return at Cardiff but the club have held talks with Real Madrid over the potential transfer of Pepe.