Paul Ince feels Manchester United have "far too many players who aren't fit to wear the shirt" and has described Jesse Lingard as "a prime example of everything that's wrong" at the club.
United were deservedly beaten 3-1 at Liverpool on Sunday, the latest low in their troubled season.
The result left Jose Mourinho's sixth-placed side 19 points behind the table-topping Reds, and 11 points off fourth position.
Former United and Liverpool midfielder Ince told Paddy Power News: "When players like Chris Smalling, Luke Shaw and Jesse Lingard are getting long-term contracts, it shows how backward they are going.
"Give them two or three-year contracts to keep them hungry, but don't spoil them when they aren't good enough for the club anyway.
"A resounding issue at the club is that there are far too many players who aren't fit to wear the shirt. Something has got to give.
"I'm not one to call for Jose Mourinho's head, but something urgently needs to change. The board need to decide whether they're going to pay him off or give him more money for players. The other option is to just scrap it all and start again. From a football point of view, the whole club is a mess.
"It's hard to bring in eight or nine players, and to get rid of a load, but I honestly believe that's what they need to do to start again. Otherwise, how far are you going to let the team slip behind everyone else?"
Lingard, who recently launched a clothing line, scored United's equaliser at Anfield in the 33rd minute when he took advantage of a mistake by Alisson Becker.
Ince said of the 26-year-old England international: "He is simply not good enough to wear a Manchester United shirt.
"All we see on social media is his new clothing line, his dancing, trips to Las Vegas and Miami. In reality, he's scored two goals all season.
"A player in his position has only managed two goals – but still has his own goal celebration?
"There are plenty of things you can do outside of football, like taking coaching badges, doing a degree, learning a language.
"You don't need to make your own clothing brand as though you are one of the best stars in the world. He needs to remember who he is.
"He's come a long way since he couldn't get in the Derby side. Besides, the way he plays, who would want to wear his clothing range anyway?
"I hate saying it – but he wouldn't have got away with it in my time. These players, when they come to United and want to be successful, should take a look at how the proper players conducted themselves.
"If you're top of the table and you've got three Premier League title winners medals, a Champions League winners medal etcetera, then you can go and create your clothing brand. But he's not.
"He's a prime example of everything that's wrong at Manchester United.
"Romelu Lukaku looks like he'd rather be anywhere else, Anthony Martial came on and instantly lost the ball, those little details make me wonder how bothered any of them are. There are no leaders or characters left at the club."
Ince, whose trophy haul with United included two Premier League titles, said that "David De Gea and Marcus Rashford aside, the players need to take a long look at themselves", spoke of a "blatant lack of desire", and added: "Are they really putting a shift in? Do they really care?
"I've been there, players start forming cliques, in the hope of getting their manager sacked and that's what we're seeing now at Old Trafford."
:: Paul Ince was speaking exclusively to Paddy Power News. To read more, visit news.paddypower.com