Manchester City could be without Edin Dzeko and Vincent Kompany until the new year.
Striker Dzeko pulled a calf muscle in the warm-up of their win at Leicester City, while captain Kompany suffered a recurrence of a hamstring injury.
After the 1-0 victory at the King Power Stadium, manager Manuel Pellegrini feared the worst.
The Chilean said he thought it "impossible" both would play again this year.
Bosnian Dzeko, who looked set for a long run in the side following an injuries to fellow strikers Sergio Aguero and Stevan Jovetic, went down moments before kick-off.
"Of course now we are without Aguero, Dzeko and Jovetic for more than a couple of weeks," said Pellegrini.
"It's a difficult situation but we will see the best way to resolve it."
Central defender Kompany started after missing the last three matches with a hamstring strain but aggravated the injury with 14 minutes remaining.
"I think he felt again a problem in his hamstring," said Pellegrini.
"That is why he didn't play on Wednesday because it was too soon. He thought he was ready to play today. Vincent said he was available to play but could not play the whole game and we see what happened to him."
Pellegrini will step up his attempts to extend Frank Lampard's stay with the champions following the expiration of his loan deal from sister club New York City.
His side will face Crystal Palace and Burnley at home and West Bromwich Albion away before the end of December.