Former Manchester United captain Roy Keane has launched a scathing attack on executive vice-chairman Ed Woodward and defenders Chris Smalling and Phil Jones after a torrid campaign at Old Trafford.
Woodward oversaw a summer transfer window alongside then-new manager David Moyes during which United made one significant signing in the form of Marouane Fellaini.
Moyes was sacked in April after just 10 months at the helm following a limp defence of the Premier League and among the contributing factors to the club's failure were the lack of additions United made in the summer.
And Keane, speaking at ITV's World Cup launch, said: "He [Moyes] had one transfer window, and it's not always down to the manager when players don't come in.
"I think Ed Woodward needs to look at himself. He's got to get deals done. I think he should have been given more time. I was happy with David Moyes. I think Van Gaal is a good choice. Only time will tell. He's managed big clubs."
A significant upheaval at Old Trafford is expected in the summer upon the arrival of Van Gaal, which has already started with the exit of Nemanja Vidic and Rio Ferdinand.
Both departures will thrust Phil Jones and Chris Smalling – who were included in Roy Hodgson's England squad for the World Cup - into senior roles in the United defence next term.
But Keane, the current Republic of Ireland assistant manager, added: "We were told two or three years ago Jones was going to be the new Duncan Edwards, Smalling was this.
"I've watched United live nine, 10 times this year and they have been none of those things. If anything I think they have gone backwards. I've actually been a big fan of them – yes, give them a chance, you say you have to give players a chance to mature but also you've got players who you say we've given you a chance and you're not taking it.
"They need to do a lot better if they want to cement their place at Man United and United to win trophies. Jones needs to toughen up. Every time I see him he is getting carried off. He's got to toughen up – he's playing for Man United. They have to recruit in the summer – they might get two.
"It's the spine of the team. United have come up short defensively and in the middle of the park they have not done enough. You watch any of the teams that are winning trophies, Jesus I'm stating the obvious, you've got to have a strong spine, goalkeeper, defender, midfielder and striker and United have been short in two of those areas. It makes it very difficult to win trophies."