Chelsea's Salomon Kalou has been sidelined for "around two weeks" after sustaining a thigh tear in Wednesday's League Cup loss to Blackburn Rovers, the Premier League club said on Thursday.
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 on Saturday.
Kalou, who played all 120 minutes of Wednesday's match at Ewood Park 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 a week on Saturday.
He could also be ruled out of the match against Premier League strugglers Portsmouth on Dec. 16.
In the League Cup, Blackburn eventually won 4-3 over the Premier League leaders on penalties to go through to the semi-finals.