Steve Bruce admitted his Aston Villa side "gifted" Sheffield United both their goals in the 2-2 draw between the sides at Villa Park this afternoon.
Villa were heading to what appeared to be an easy home win when Albert Adomah converted a penalty and Mile Jedinak added a second inside the opening 10 minutes.
But United picked themselves up off the floor and salvaged a point following three successive defeats, thanks to two goals from former Birmingham City striker Clayton Donaldson.
And the Villa manager admitted: "The manner of the game was totally disappointing. As a manager or coach the one thing you cannot legislate for is individual error.
"It cost us in a big game last week and it cost against Sheffield United. Unfortunately after a wonderful start and scoring twice we gifted Sheffield two goals.
"That was disappointing because one area where we have been rock solid is in defence. But we have been hit by injuries."
He added: "We got ourselves in a wonderful position with two early goals and we needed to see out for 15 or 20 minutes and before you know it was a difficult game with everyone on edge.
"I will look to freshen up the side for the game at Brentford with several players waiting patiently in the wings for their chance. We will have to dust ourselves down and go again. It's simple as that.
"You could say we have only lost one in the last seven but there have been three draws in the last four."