Manchester City boss Manuel Pellegrini says his side did not deserve to lose the derby as the Citizens failed to close the gap at the top of the English Premier League.
The Citizens suffered their ninth defeat of the season and now trail leaders Leicester City by 15 points.
They will assess goalkeeper Joe Hart and winger Raheem Sterling after they both suffered injuries against the Red Devils.
"We did not deserve to lose," Pellegrini is quoted as saying by BBC Sport.
"We dominated the game from the first minute we were the only team who wanted to play the whole game but we missed three or four chance to score.
"Every player has bad days, [Martin] Demichelis was nervous, it was not good for him to continue.
"We didn't score goals but that is not his fault.
"We will see about Joe Hart and know in the next two or three days how long he will be out for."
