Peterborough boss Grant McCann demanded immediate improvement after his side’s miserable run continued with a 2-1 home defeat to Barnsley.
McCann kept his players locked in the dressing room for more than an hour after a fourth successive defeat in all competitions.
Posh fell behind to a terrific first goal in English football from Tykes ace Luca Connell in the 11th minute.
They levelled with their first attempt on goal as Jack Taylor headed in a Kwame Poku cross 10 minutes later.
But it was Barnsley who succeeded in finding the net again in the second period to bag a fourth straight win.
Adam Phillips fired in his fifth goal in six games just after the hour when his 25-yard blast was fumbled into his own net by Posh keeper Lucas Bergstrom.
McCann said: “What was said will stay between myself and the players, but the reality is we need to get better.
“We’ve been on a terrible run losing five of our last six games – including three in the league – and it’s a disappointing night for us.
“There was nothing in the game until Barnsley went 2-1 up. It was two decent teams going at it hell for leather with relatively few chances for either side.
“But we conceded a really sloppy goal and after that we had absolutely nothing about us. We went away from everything we are good at.
“Lucas is going to be a top keeper, but he knows he needs to save that. It’s a routine save that he practices every single day, but unfortunately tonight it went under his gloves.
“But he’s been brilliant since he’s been here and we’re just really disappointed that we didn’t show our fans anything after being 2-1 down.”
A much happier Barnsley head coach Michael Duff said: “It was a very, very good away performance.
“We passed the ball really well and showed resilience at the end when Peterborough were throwing five players up at our back line.
“We had Luca in during the week as he scores a lot of goals in training and we feel he is more than just a player who sits.
“We were disappointed not to be further ahead and when they scored with their first shot on target you’re thinking ‘here we go’, but we didn’t let it affect us.
“We said at half-time that it’s not ability alone which will win the game – it’s mentality and togetherness. We showed all three of those qualities.
“We know what Adam can do and while I’m sure the Peterborough keeper will feel he probably should have done better, it’s a good goal from our point of view.
“The togetherness has been really growing and of course the results help with that.”
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