The club have spent around £850million on players in the six and a half years since Sir Alex Ferguson retired but have only finished in the top four twice since.
They have the Premier League’s highest wage bill but are currently 30 points adrift of leaders Liverpool and are five points off fourth-placed Chelsea.
Failure to qualify for next season’s Champions League for a second season running would be a huge hit to their income, although they could still make it by winning this season’s Europa League.
And Neville believes that the time has come for Man United to ditch the former investment banker.
“I can’t change the ownership of United, no one can. I’m struggling to understand why the ownership have persisted in trusting that management team to oversee the building of a Premier League title winning team since Sir Alex left,” he told the Gary Neville Podcast.
“I saw a statistic two weeks ago that United have the second-highest wage bill in the world. And that’s the squad they’ve got. It’s unforgivable. It really is.
“I can’t believe the investment that’s been put into the squad in the last five, six, seven years and you end up with that out on the pitch.
“If you don’t lose your job for essentially overseeing that investment, that wage bill, and putting that team out on the pitch then I have to say something is really wrong.
“There’s real talent in that executive team … but in terms of what the club needed to do for a number of years now is put the best in class football operators into that club and they’re not doing it. They’re not doing it and it’s a mess.”
Woodward is the highest paid director in the Premier League with annual earnings last season of £3.16million.
The Glazers, who own Man United, were subject to a series of angry chants during their win over Norwich at Old Trafford on January 11.
Resentment towards Woodward and the club’s management has been building over the last couple of years with the Glazers being targeted by fans ever since their takeover in 2005.
Man United have had setbacks in the January transfer window having lost out on Erling Braut Haaland to Borussia Dortmund – the striker then scored a 20-minute hat-trick on his Dortmund debut on Saturday.
It’s not clear whether Portuguese midfielder Bruno Fernandes will sign with Man United reportedly struggling to agree a fee with Sporting Lisbon for him.
They’re struggling for options up front after manager Ole Gunnar Solskjaer confirmed Marcus Rashford is out for up to three months with a double stress fracture in his back.
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Neville also believes his former club should coordinate a plan behind the scenes to ensure they get back on top but doubts whether the club has the expertise in the right positions to do so.
“Somewhere in the background at United someone has to be plotting the downfall of Liverpool and getting back above them,” Neville added. “That’s going to take wise, smart, good people, and I’m not sure they’re there.
“There is an element of you that has to accept Liverpool are a huge football club, but there are some huge decisions that need to be made in that boardroom at United. I can’t believe the squad they’ve ended up with after the investment made.
“The thing that should shock the owners more than anything, they should see that last minute goal (from Mohamed Salah on Sunday) – they should have that playing on repeat every single day in their office over in America – Liverpool’s fans singing, ‘We shall not be moved.’
“I feel emotional. I was proud to be part of a great United team, I lived through a difficult childhood as a United fan, watching Liverpool win every single title it felt like and then United started to win and maintained it for a long time.”
