Gary Speed labelled his Sheffield United team "unprofessional" after a 3-0 defeat at Ashton Gate sent them closer to the wrong end of the npower Championship table.
Brett Pitman profited from two first-half penalties to put Bristol City in command and the visitors' problems worsened when Richard Cresswell received a straight red card for fouling Marvin Elliott just before the break.
"Decisions have gone against us this season," said Speed. "But to concede two penalties and have a man sent off is unprofessional and we showed a lack of discipline at times.
"I thought the first penalty was the correct decision. The second was more debatable because their lad has hit a shot from about a yard away from our defender, who was judged to have handled it.
"The sending-off was silly. It may have looked harsh, but Cresswell went in with two feet raised and you cannot do that in the modern game.
"You see tackles like that punished with red cards on television every week. Even at 2-0 down I fancied us to get something from the game, but going down to 10 men made it impossible.
"Irrespective of the decisions, we didn't play well enough. Bristol City were the better team throughout and when that happens you have to roll up your sleeves and really battle."