Knights coach Nathan Brown said some of his players should "hold their head in shame" and he vowed to make changes for next week's clash against Manly after a 28-26 loss to Wests Tigers left Newcastle's finals chances hanging by a thread.
Brown slammed his side's defensive attitude after they conceded three tries in 18 minutes following a strong 12-0 lead start to the game.
The Knights had no issues laying on points but were their own worst enemy through defensive lapses and errors at crucial times as they slumped to a fourth consecutive loss.
"Our last three or four weeks we've slowly declined in attitude and resilience around our defence," Brown said.
"When we lost five to start the year we were still a good defensive team. At the moment we've got different people picking and choosing when it's important to put the effort in.
"Our defensive coach certainly hasn't changed anything, maybe a couple of people thought that it's acceptable to not put the right effort in.
Match Highlights: Knights v Wests Tigers
"Tonight is Mark Hughes night and that's a massive night for our club . . . the mark of a person is someone that does something for others for nothing and that's what Mark Hughes does and there's certainly some blokes who should hold their head in shame for what they dished up tonight."
Brown indicated the Knights spine were not the problem after all five players in the backline crossed for tries courtesy of their playmakers, hinting the forward pack were in the firing line.
Only NSW representatives David Klemmer (168 metres) and Daniel Saifiti (145 metres) put a dent in the Tigers' defensive line.
"There will be certainly some changes next week that will be unforced changes, that is a 100 percent guarantee," Brown said.
"We stuck loyal with the boys this week. It's disappointing, we've led 8-0, 12-0, 12-0 and are basically mirroring the path of where Canberra were last year.
"Apart from the Manly game we've led so many games here where we've been beaten by one, by two, by four."
Newcastle could find themselves outside the top eight by the end of round 19 with clashes against the Sea Eagles, Eels and Cowboys to come before a rematch with the Tigers in round 23.
Brown remained hopeful his side could turn things around in the remaining six weeks and make a run at a first finals berth since 2013.
"You'd like to think we can get it back but we'll have to make some changes to do that," Brown said.
"We've just got a few people we need to change. There's plenty of forwards who are busting for an opportunity.
"We scored 26 points and dropped it over the tryline. Points aren't the issue, it's our defence that's hurt us."