Robin van Persie has warned Donny van de Beek to expect a far greater challenge at Manchester United.

The Ajax star has completed a medical with United ahead of a £40m transfer.

And van Persie says the midfielder should prepare himself for a much different life at Old Trafford.

Writing in De Telegraaf, the former United and Arsenal striker said: "Donny is being hailed as a major purchase from Manchester United, but he will find that those other 22 players have been brought in as a 'major purchase' before.

"One had an even bigger transfer than the other. It means that he has to be there immediately and he has to mentally adjust to that. Because Manchester United is in every way a beast of a club.

"You can have a bite to eat and people will wait an hour for you to have their picture taken with you. Very classy. But if things go badly, you will be put under a magnifying glass. Both privately and on the field.

"When I was with Marcus Rashford recently, I asked him how often he should do something commercial now. He couldn't remember the last afternoon off after a workout. That is a bit different than taking a siesta after a training. He won't get another day of rest."

On van de Beek as a player, van Persie added: "His runs are his greatest weapon. He is also able to play sixty matches a year. Relaxed parties are no longer an option. It is precisely against Fulham or Crystal Palace that you have to work the most."