The Serbian was stretchered off the sodden pitch during the second half of City's 1-0 Asia Trophy triumph over Sunderland.
|ASIA TROPHY TRIUMPH
|MATCH REPORT: Edin Dzeko's goal makes the difference as Man City beat Sunderland|
"The doctor has to see him [on Sunday] when we arrive back in Manchester," Pellegrini told reporters after the game. "I am concerned but it's better to wait.
"It wasn't the pitch, though. He got a kick on his ankle but it was just part of the game."
Edin Dzeko's ninth-minute goal was the difference between the two sides but the manager highlighted the efforts of new faces Alvaro Negredo and Jesus Navas.
"I know Negredo very well," Pellegrini added. "When we brought him here, we knew he was a successful player and in these two games he's demonstrated what he can do.
"Jesus is the same as Negredo. He gives our team a different option. He is very a difficult player [to play against]."
|14/1||Alvaro Negredo is 14/1 with Bet365 to be the Premier League's top scorer
"Some players still don't know what I want from them exactly but we still have a long time," the Italian observed. "Even some top players are never going to change their mentality but this process can be up and down.
"There is no way we are over-training the players, though. Last year some of them under-trained. We have to be careful because we have a plan, we know we can pay a price."
Di Canio also played down concerns about the condition of the playing surface at the Stadium of Light.
"The pitch was difficult but it was also difficult for them because they have fantastic ability," he said. "Thinking about it [the night before], I thought it would be a worse pitch but they put a lot of sand in the middle of the pitch and actually it wasn't that bad."