Roy Keane accused Manchester United players of being "bluffers" after their latest harrowing Premier League defeat on Sunday, while fellow club legend Gary Neville admitted the club are in a "desperate situation."

United were thrashed 4-1 by Newcastle United on Sunday -- a 14th league defeat that leaves them 14th in the table -- and as well as pointing the finger at manager Ruben Amorim after the game, Keane took exception with Bruno Fernandes' post-match interview.

"We lack being more fearless, being more brave," club captain Fernandes told Sky Sports. "Today was not the case because we ended up conceding goals by trying to be brave.

"My teammates -- I only get frustrated with them because I know how good they can be. I know how tough it is to represent this club."

Keane, a former United captain himself who made 480 appearances for the club, said Fernandes was surrounded by "bluffers" as teammates.

"To be fair to Bruno Fernandes he fronts up, but to me it's just soundbites now," Keane, now a pundit on Sky, said.

"He was talking about his teammates and belief, but what about his right-back [Diogo] Dalot, who didn't put a leg out to tackle? I hope he is pulling him in the dressing room because he keeps talking about having belief in his teammates, but real good teammates put demands on each other.

"It must be tough playing in that midfield when the expectation is on him because that's unfair on him. But when he's doing his chats about supporters and this, to me it's just soundbites. There is no meaning to it. I'm not sure this United group are an honest group.

"The best players I played with put demands on me and wouldn't tolerate me cutting corners. That's what really good teammates do. These aren't teammates, they are bluffers."

United face a crucial quarterfinal second leg against Lyon in the Europa League on Thursday, with Europe still offering Amorim's side a potential route into the Champions League next season.

But Neville, who spent his entire playing career at United, said the latest defeat was still "worrying."

"I don't think there's a lack of effort," Neville told NBC. "They're giving it their all. But they're so below the standard and quality you need at that football club all over the pitch.

"Other than Bruno [Fernandes] and Amad Diallo maybe, I can't think of any of them I would hang my hat on.

"It's a really desperate situation. The squad is so poor on quality. They have old players, they have young players who are nowhere near it, they have a group in the middle ... It's a worrying situation."