The 17 year-old signed pro terms with United this week, announcing the agreement on social media yesterday.
Upon losing Hoogewerf, Ajax academy chief Saïd Ouaali lamented: “Last week Dillon indicated that he will leave the club for a foreign club. We wish him a lot of success.
"We know that we have done everything we can to keep him. Ultimately, however, he can make the choice and he chooses a foreign adventure.
“We know that we have created all the conditions at De Toekomst. Ultimately he can make that choice."
He added: “Of course we want to keep our top talents with us, so I am very happy that the other talents have stayed with us. That has been the case in recent years and that remains our goal."