Louis van Gaal has made a big mistake by saying he needs three years to turn the club's fortune around according to Gordon McQueen.
Van Gaal was appointed as manager of the Red Devils after David Moyes was sacked 10 months into job.
Earlier in the season, the Dutchman said he could be judged after three months as United boss but on Friday last week he changed his thought after reassessing and said he needed three years.
But United legend McQueen doesn't reckon he needs that amount of time to get the Reds going.
“There is no chance that Van Gaal will get three years to turn round the club," he told Goal. "He’s made a big mistake there and I’m surprised he said it.
“He already lives and breathes United so must know that is never going to happen. Perhaps he has already realised it’s a tougher job than he first feared.
“His predecessor David Moyes didn’t get three years, so why should he?
“He will get longer than Moyes because his CV is more impressive and he has proved he can do it a big clubs, but expectancy levels at United are still high and he has to show major progress this season.
“A top-four finish is a prerequisite, particularly after the club being out of the Champions League this season. As it stands, there are no guarantees on that score.
“United beat Crystal Palace 1-0 on Saturday at Old Trafford and we should feel grateful for the three points, but that is where the club is at the moment – two years ago that would have been a gimme.”
The former United defender also commented on the Reds' defence which is a critical area that needs improvement.
“United have had concerns in central defence since Rio Ferdinand and Nemanja Vidic started having injury problems, but they've not addressed it.
“I expected Van Gaal to sort it out, but while Marcos Rojo might come good in time, he’s also out injured with a dislocated shoulder.
“There is a frightening lack of experience in central defence. I like the look of Paddy McNair, but he’s been pitched into defence even though he is really a midfielder.
“He needs to learn his trade, and it isn't easy. I had Norman Hunter alongside me when I went to Leeds, and when I came to United, it was Martin Buchan. Who has McNair got? Chris Smalling and Phil Jones.
“Injuries account for the dozen or so central defensive partnerships there has already been this season, but it doesn't matter who you have, unless you have a settled unit you are going to struggle.
“I hope Van Gaal makes central defence his priority in the January transfer window, if not it will cost him dear.
“The problem is that good ones don’t grow on trees and transfer fees seem to go through the roof in January. Everyone knows it’s a problem for United and they can name their price.”