The central defender has not featured for his club since before the international break and the Chilean explained that his skipper has not yet recovered from a thigh injury.
"Vincent is still injured, so he will not have a chance to play this game," Pellegrini told the press, though noting that the rest of the squad, including Jack Rodwell, are all fit and available.
"It's a tough game for Manchester City," he added. "We are one point behind them and we must play well if we want to win."
Sergio Aguero comes into the game in fine form after scoring twice against CSKA Moscow in the Champions League and the City boss was effusive in his praise for the Argentine.
"He's a top player," Pellegrini enthused. "I'm always talking to him. For me, he's one of the top five players in the world.
"I hope in the future he continues to be an important player for the club."
Wednesday's match in Russia caused controversy after several players reported racist chanting from the home fans towards Yaya Toure and, while Pellegrini claimed not to have heard the abuse, he warned that "UEFA must make the right decision" on the issue.