Manchester City defender Aleksander Kolarov is set for up to a month on the sideline with a calf injury.
The Serb, 28, suffered the problem during the warm-up before Sunday’s derby win against Manchester United.
The left-back missed the 1-0 win over United and is unavailable for Wednesday’s Champions League game against CSKA Moscow.
“Kolarov has a muscle injury in his calf son he will be out for at least one month. Well, I am not a doctor, but I suppose that,” manager Pellegrini said in his pre-match press briefing on Tuesday.
He is also set to miss league matches against QPR, Swansea and Southampton, as well as City’s penultimate fixture in the group stage of the European Cup at home to Bayern Munich.