Chelsea's Salomon Kalou has been ruled out for "around two weeks", the Premier League leaders said, after sustaining a thigh tear in Wednesday's League Cup loss to Blackburn Rovers.
Chelsea's statement said the 24-year-old Ivory Coast star had "sustained a minor tear to his upper left thigh" and that the injury would sideline him for "around two weeks".
The Blues, five points clear at the top of the table from champions Manchester United, are away to Manchester City in the league today.
Kalou, who played all 120 minutes of Wednesday's match at Ewood Park, where Blackburn eventually won 4-3 on penalties to go through to the League Cup semi-finals, now seems set to miss the trip to City's Eastlands ground, Tuesday's Champions League game against Apoel Nicosia and the league match against Everton today week.
He could also be ruled out of the match against Premier League strugglers Portsmouth on December 16.