Furious Leeds manager Garry Monk ruled his team’s second-half display was unacceptable after they slumped to a 2-1 defeat at home to Birmingham.
Birmingham hit the front at Elland Road when Jacques Maghoma calmly fired home following a superb counter-attack.
Leeds got the equaliser that their superior possession and energy deserved when Hadi Sacko scored following a terrible goalkeeping blunder from Tomasz Kuszczak after 27 minutes.
But Birmingham came out a different proposition after the break and got their reward 10 minutes after the restart when Michael Morrison smashed home from six yards after Leeds failed to clear a corner.
Kuszczak then made amends for his early blunder when he turned away Stephen Gleeson’s sliced clearance and saved well from Marcus Antonsson in the closing stages.
Monk said: “I did not like that softness and I told the players that. When you are on the pitch you have to be a man, you have to put your body on the line and suffer.
“We gifted that game to Birmingham and I will not accept that. We did not have the determination and desire we needed in the second half.
“We have a young group of players, but you are in a man’s world and you have to do more than that.
“We are not here to put cotton wool around anyone. The players have the capability but they have to grow up and grow fast.
“They have to have a strong mentality. The better mentality you have, the higher up the league you go.
“We have to be mentally stronger in situations like today. Birmingham were not doing much, they then put more battle into it and they got something from it.”
Delighted Birmingham boss Gary Rowett hailed his side’s defensive resilience and character.
He said: “We got into good areas often and limited Leeds in the second half. We were very strong and it suits us playing away from home.
“Leeds did well in the first half and caused us bother with their runners.
“We showed character in the second half and were in control of the game, We did not look under threat, only when we caused ourselves trouble.
“It was a really strong, organised and tactically concentrated performance.
“I thought we saw the game out very professionally. We know what we are as a team and we are getting better at it.
“The keeper is disappointed with the goal, he made a mistake, players make mistakes and you hope they don’t make too many.
“He shouldn’t have scored from there but it was an honest mistake and I will support him. Leeds were bright and I’d be disappointed if I was Garry Monk to have lost the game.”