The Owls had a late Julian Börner goal ruled out with the score at 1-1 and thought they had won it before defensive mistakes from the back allowed North End to take the win at Hillsborough.
Speaking straight after the match Monk also seemed to question the decision to rule out the German’s header, admitting he was unsure why it was scratched out. Replays suggest a foul was given against Joey Pelupessy on Preston keeper Declan Rudd.
But the Owls boss refused to let that be an excuse for a lack of solidity at the back.
“The main factor is that we have to be much, much better at the fundamentals,” Monk said. “Especially from a defending point of view in terms of winning your individual battles and the basics of those fundamentals. It has to be much, much better.
“In terms of concentration, I spoke during the week to the players. In critical moments we have to be better. We have to be able to focus in those moments, no matter what the circumstance is. It comes down to the fundamentals of defending.”
Asked whether he had spoken to referee Tony Harrington about the decision to rule out Wednesday’s late effort, Monk told The Star: “I think one thing I’ve learnt in management is that there is zero point in speaking to the referee or anyone with decisions. You can’t change them, right or wrong.
“The information from the fourth official is that the linesman had said there was big interference with the keeper.
“I didn’t see it, I don’t think anyone else saw it. The fact the ball went into the top corner, I’m not sure whether interference or not really mattered. The keeper made a dive for it and could never get there.
“It was a bitter blow, coming from a position where you’re more than likely to win.”