Manchester City could have the pair back in first-team training next week, while Samir Nasri is progressing well and is in line to be available for selection again soon
Aguero injured his hamstring in the 5-1 victory over Tottenham at the end of January, but stepped up his recovery last week.
Fernandinho had picked up a thigh problem prior to the 1-0 defeat to Chelsea at the Etihad Stadium, but recently returned to light training.
And Pellegrini told reporters on Tuesday that both players are due to make a full recovery and return to first-team training in a week, ahead of the Champions League clash with Barcelona.
Pellegrini also indicated Samir Nasri is back in first-team training and progressing well after suffering a knee ligament injury.
Javi Garcia is also available for selection, but defender Matija Nastasic has a knee problem.