Reports emerged this morning claiming that the Spain international has not responded well to treatment on a hamstring injury, which he picked up during City's 2-1 victory over Manchester United on Monday.
"We will decide on Sunday morning on David," Mancini told the club's official website. "We don't know if it's possible for him to play or whether it might be a risk if he does.
"He has a chance, but I don't think he can recover fully. He may be able to play some part, but we will make a final decision as late as possible."
City will face either Millwall or Wigan Athletic in the final if they defeat Chelsea.