The game was the first on-field meeting between Terry and Wayne Bridge following the Chelsea defender’s affair with the mother of the City star’s son.
Ancelotti told Sky Sports, when asked if the trouble had affected his side: “No I don’t think so.
“We lost the game because we made mistakes. In the first half we played a good game, we had the advantage. We lost because Manchester played a good game and we made mistakes.”
Ancelotti also defender goalkeeper Hilario, who could have done better with City’s first two goals.
He admitted: “I think that Hilario could do better, but also the defenders could do better in the situation. We lost the balance when we had the game in our hands.
“I think we made mistakes in this game at the end of the first half and the start of the second half and we lost the game.
“We conceded on the counter-attack and lost our balance in that period. We conceded two goals and after that the game was not difficult and we didn’t have the possibility to come back into the game.”
Manchester United are just one point behind Chelsea on the Premier League table.
Ancelotti added: “It is more difficult for us and more easy for them.
“They are only one point down. I respect Manchester United and Arsenal and we have to work for this.
“We have to wait. Now there is an international break and next Sunday in the FA Cup we want to have a good reaction.
“We lost, we are disappointed, it was not a good match but we have to look forward because we are still top of the league.
“We have to stay focused and improve and do our job to avoid these mistakes.”