The Belgium international, who has been unavailable for the Premier League champions with a calf injury, was thought to be making his comeback following next week's FA Cup fifth-round clash against Leeds United.
"We are optimistic," Mancini said in a press conference. "He trained yesterday, and two days ago. After today we will decide."
The Italian boss also confirmed that brothers Yaya and Kolo Toure will be available for selection following the Ivory Coast's exit from the Africa Cup of Nations.