Wilder says his team need to “own” their relegation after collecting just 16 points and conceding 97 goals in 35 games – the worst top-flight defensive record since Swindon Town shipped 100 goals in the 42-game 1993-94 season.
The Blades spurned several opportunities to add to Anel Ahmedhodzic’s early opener at St James’ Park before Alexander Isak’s double, efforts from Bruno Guimaraes and Callum Wilson, and an own goal from Ben Osborn completed a miserable afternoon for the South Yorkshire club.
“There’s a reason why [the second-half collapse] happens,” Wilder said. “It’s an incredibly young side and there’s a complete lack of leadership out there. I thought at times I was going to have a heart attack in terms of trying to get the messages on.
“There have been plenty of games where we have been put to bed early, but today we could have been 3-0 up at half-time.
“Newcastle upped their game and got a head of steam. Then our old mistakes start to fall in and goals go from two to three to four to five pretty quickly.”
With Ben Brereton Diaz, Mason Holgate, James McAtee and Yasser Larouci due to return to their respective parent clubs on 30 June and Jayden Bogle, Oli McBurnie and goalkeeper Wes Foderingham all out of contract in the summer, Wilder has plenty to think about this summer but has no intention of leaving Bramall Lane.
“We’ve got so much work to do on the training ground. We have to have a proper pre-season,” he said.
“I’ve still got another year left of my contract. I’d like to think that the supporters can trust me [to stay].”