City head into Sunday's meeting at OId Trafford having fallen behind United and nine points adrift of Premier League leaders Chelsea following a 2-1 loss to Crystal Palace on Monday.
And Manuel Pellegrini's men could be without their skipper at the back because of a hamstring injury suffered during the second half of the defeat at Selhurst Park.
Pellegrini said: "He [Kompany] could finish the game the other day but he couldn't work the normal way all week.
"We'll see [on Saturday] if he can play or not. I always say the same, it's always better with Kompany but if he can't play, we have a squad and we will replace him."
Striker Wilfried Bony is definitely out with ankle and knee concerns, while Stevan Jovetic and Dedryck Boyata are both doubts.
"Stevan Jovetic has a muscle injury," Pellegrini added. "Bony twisted his ankle and knee before Palace and he won't be ready for this game. Boyata has a problem with his knee."
Turning his attention to the strong recent form of Louis van Gaal's United - who have lost just twice in the Premier League since a 1-0 defeat at City at the start of November - the Chilean said: "I'm not impressed because Louis van Gaal's teams are offensive teams who try to win titles.
"United bought a lot of very good players in the summer – [Angel] Di Maria, [Ander] Herrera, [Radamel] Falcao, [Juan] Mata the season before – and [Daley] Blind.
"They bought a lot of very good players – the strange thing was why they weren't doing it before but it's no surprise [they are doing well now].
"I think that United have a lot of respect for our team as we dominated not only the derby in the last few years but also the Premier League.
"I understand we are not having the away results we want - 2015 is not a good year for us for this but the motivation is to win, always."
