Captain Ron Vlaar says Aston Villa must cut out the mistakes if they are to avoid a nervous final few weeks of the Premier League season.
Villa, who had beaten leaders Chelsea 1-0 in their previous home game, were brought crashing down to earth with a humbling 4-1 defeat by Stoke on Sunday.
Manchester United are up next at Old Trafford, and although Villa are nine points above the relegation zone, Vlaar says that they cannot afford a repeat of their performance against the Potters.
"If the discipline and the effort we had last week (against Chelsea) drops by only one per cent, and if the focus is not right - I'm not saying it wasn't right (against Stoke) but it has to be spot on - then we are not as good as we think," he told AVTV.
Christian Benteke got Villa off to a superb start when he fired Villa in front after just five minutes, but a series of defensive errors allowed Stoke to cruise to just their second away win of the season.
Vlaar wants to move on quickly from the defeat, which caused Paul Lambert's side to slip into the bottom half of the table.
"We have to get rid of games like this and learn," the Dutchman said.
"Everyone is down after such a big difference from the Chelsea game. We made mistakes all over the pitch. You really want to get a good streak of winning games and it doesn't happen now.
"We have to look in the mirror and say honestly that we made too many errors. But we have come back and stepped up again, and we have to do it again."
Boss Lambert was unhappy with the "lethargic" effort of his players, but he thinks they may actually play better against Manchester United next weekend.
"Whatever happened in this game, Old Trafford would take care of itself," he said.
"Manchester United is a great game to play in and a great stadium to go to. It's a game similar to Chelsea in that no-one expects anything from us. But we will go up there and try to get a result."