The likes of Marco van Basten, Ruud Gullit and Wesley Sneijder are not sure if Matthijs de Ligt is good enough for the Premier League.
The former Netherlands internationals have some doubts about Erik ten Hag choosing to bring his ex-player to United.
Per The Mirror, Van Basten said: “De Ligt has to start performing now - no more excuses. Erik ten Hag must also ensure that he has a good and fit selection. But De Ligt seems to be injured everywhere he plays.
“That does remain a question mark. I do hope the best for him, but if you see his progression he hasn't gotten much better since he left Ajax. I worry that De Ligt goes full out everywhere on the pitch and has not really developed any anticipation yet.”
Sneijder added: “It is quite remarkable that he (De Ligt) has never found a base to play regularly.
"I thought Germany would suit him better. They play a bit the same as the Netherlands, trying to solve things from the back with footballing solutions. I had a good feeling about his game in Germany.
"But England is much more physical, with big and fast players. It is difficult to assess whether he fits there. I really don't begrudge him the move. He is a studious boy who is at the front of training every day.”
Gullit added: “Giorgio Chiellini waxed lyrical about him (De Ligt) and he also thought it was strange that he didn't play more for Holland. I think he's a great guy. I do hope he makes it in England. But this is the Premier League - and you have to work hard to succeed."