The Belgium defender suffered a knee injury in a clash with Cristiano Ronaldo late in Wednesday's Champions League encounter with Real Madrid at the Etihad Stadium.
The 26-year-old completed the 90 minutes of the 1-1 draw but required treatment after the game and left the ground on crutches.
His place for the champions' Premier League trip to Stamford Bridge is in doubt but Mancini has not yet ruled him out.
The Italian said: "We need to wait until tomorrow (Saturday). I hope we can recover him for Sunday because Vinnie is strong."