Leeds threw away a two-goal half-time lead before snatching a dramatic stoppage-time equaliser in the 3-3 Championship draw at Brighton. Whites boss Simon Grayson was annoyed that his side could not see the game out from a commanding position.
He said: "We can't keep conceding goals and my players must understand it.
"We shouldn't be delighted at getting a point right at the death from the situation that we were in.
"But, on the positive side, we have taken seven points out of nine in the last three games and will always score goals. It's just a mental approach that individuals need to act on for themselves."
Grayson admits concern that defensive frailties could cause his side problems as the season progresses.
He added: "To go from 2-0 up to be losing 3-2 with six minutes left is worrying. That kind of thing could lead to us missing out on the play-offs.
"We must make sure we get clean sheets. We need to see games out. We came back again to get a point, but it was frustrating."
Brighton counterpart Gus Poyet admitted that it was a point gained under the circumstances.
He said: "We were practically out of the game at 2-0 down so we need to be realistic.
"Credit to the players to get back to 2-2 and then score again.
"But there's no excuses. We made a great effort only to concede in the 92nd minute. I'm not happy with 3-3, but it can be a point gained from the position that we were in.
"I have a mixture of emotions, and was bitterly disappointed at the end because we didn't defend well when Leeds got their equaliser."
The Seagulls are still unbeaten at home since switching to play at the new Amex Stadium.
He added: "I was pleased with the mental strength we showed. We are a good team and difficult to beat, but playing two games in 48 hours [following Wednesday's Carling Cup loss to Liverpool] wasn't easy."