The Belgium defender was forced off during the first-half of Thursday night's 3-0 win over Aris Salonika. With so many injuries decimating his squad at present, Mancini can ill afford to lose such an influential member of his first-choice starting line-up, especially with games coming every three days at present.
"We won't know what has happened until Friday when we see what the situation is," said Mancini.
"We have a lot of injuries at the moment, so I hope it is not serious and he will be available for Sunday."
City tackle Fulham at Eastlands this weekend as they continue their quest for a top four berth.
Whether they will throw all their big name strikers at Mark Hughes' men, as Mancini did Thursday night, is open to debate.
Edin Dzeko profited most from the tactic, scoring twice in the opening minutes to help seal a last-16 meeting with Dynamo Kiev. However, Mancini can see a flaw in selecting the Bosnian, in addition to Carlos Tevez and Mario Balotelli.
"I thought we did well and in the first half I was very pleased," said the Italian.
"The problem comes when we don't have the ball. If we don't close down every situation, it could be difficult for us.
"We can play this formation, but not often, unless we improve."