Reds boss Gerhard Struber was very disappointed with his side's display on Tuesday night.
A poor first 45 for Barnsley saw them 3-0 down at the break as Preston took advantage of defensive mistakes.
Struber was quick to admit that the performance was one he hasn't seen and wasn't worthy of excusing.
“This was absolutely the worst performance since I have been here in Barnsley." Struber told us, post-match. "The first half was not to our standard at all and for me it is clear we did not play in a professional style. I can't understand it.
"It was not good enough to pick up points or to stay in this league. It was absolutely not my style and not the style the team should show the fans. This was not what we expect from a Barnsley team.
"I cannot say the right words about the first half. It is a new feeling for me. It’s a raven black day for me and my players.”
In the early stages, Barnsley could have gone ahead when Conor Chaplin shot wide and Marcel Ritzmaier warmed the hands of visiting 'keeper Declan Rudd.
But mistakes arose, and the Reds were punished.
“We made such big mistakes." Gerhard stated.
"It was like before I came to the club when those mistakes were normal. I've seen those games.
"We haven’t had these mistakes in the last games but my team crashed in this game. We made mistakes like amateur players. This is not enough to stay in the league.
"I can make no comment on the mistakes for the second and third goals, they were absolutely crazy, what can I say?"
The Head Coach couldn't hide his frustration and referred to the hard work ahead as Barnsley look to defy the odds and remain a second tier outfit.
"It’s normal that you can lose games but it is how you lose a game. The opponent’s goals were so simple, so simple because we gave them. The mistakes crashed our spirit and our energy. The body language after the goals was not OK and that was the big surprise to me.
"I will not accept this. I have learnt more about this group.
"The next weeks are important, because it guides our future.”