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' trip to Stamford Bridge is in doubt but Mancini has not yet ruled him out.
The Italian said: "We need to wait until tomorrow. I hope we can recover him for Sunday because Vinnie is strong."Wary
Mancini is wary of a Chelsea side rebounding from a week of turmoil.
Chelsea, with their Champions League title defence badly hanging by a thread, sacked manager Roberto Di Matteo in midweek and replaced him with Rafael Benitez.
The club have also been heavily criticised after the Football Association dismissed their allegations of inappropriate language against referee Mark Clattenburg.
Mancini said: "Usually when one team changes a manager the game after for the opponents is very difficult. For us, I think it is more difficult.
"Chelsea is a good team with Di Matteo and will be a good team for Benitez. They have good players.
"Until three games ago they played fantastic football and were on the top."